ESSA Bancorp (ESSA) 10-Q 10 May 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2017	May 08, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	ESSA
Entity Registrant Name	ESSA Bancorp, Inc.
Entity Central Index Key	1,382,230
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		11,586,202

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
ASSETS
Cash and due from banks	$ 26,495	$ 31,815
Interest-bearing deposits with other institutions	9,948	11,843
Total cash and cash equivalents	36,443	43,658
Certificates of deposit	1,000	1,250
Investment securities available for sale, at fair value	395,315	390,410
Loans receivable (net of allowance for loan losses of $9,366 and $9,056)	1,208,497	1,219,213
Regulatory stock, at cost	13,961	15,463
Premises and equipment, net	16,539	16,844
Bank-owned life insurance	37,112	36,593
Foreclosed real estate	3,315	2,659
Intangible assets, net	2,160	2,487
Goodwill	13,801	13,801
Deferred income taxes	12,171	11,885
Other assets	18,415	18,216
TOTAL ASSETS	1,758,729	1,772,479
LIABILITIES
Deposits	1,238,375	1,214,820
Short-term borrowings	120,951	129,460
Other borrowings	199,168	230,601
Advances by borrowers for taxes and insurance	9,115	4,956
Other liabilities	12,351	16,298
TOTAL LIABILITIES	1,579,960	1,596,135
STOCKHOLDERS’ EQUITY
Preferred Stock ($0.01 par value; 10,000,000 shares authorized, none issued)
Common stock ($0.01 par value; 40,000,000 shares authorized, 18,133,095 issued; 11,574,829 and 11,393,558 outstanding at March 31, 2017 and September 30, 2016)	181	181
Additional paid in capital	180,729	181,900
Unallocated common stock held by the Employee Stock Ownership Plan (ESOP)	(8,947)	(9,174)
Retained earnings	89,299	87,638
Treasury stock, at cost; 6,558,266 and 6,739,537 shares outstanding at March 31, 2017 and September 30, 2016, respectively	(80,129)	(82,369)
Accumulated other comprehensive loss	(2,364)	(1,832)
TOTAL STOCKHOLDERS’ EQUITY	178,769	176,344
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 1,758,729	$ 1,772,479

Consolidated Balance Sheet (Un3

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Statement Of Financial Position [Abstract]
Allowance for loan losses	$ 9,366	$ 9,056
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	18,133,095	18,133,095
Common stock, shares outstanding	11,574,829	11,393,558
Treasury stock, shares outstanding	6,558,266	6,739,537

Consolidated Statement of Incom

Consolidated Statement of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
INTEREST INCOME
Loans receivable, including fees	$ 11,799	$ 12,805	$ 24,050	$ 24,379
Investment securities:
Taxable	2,043	1,903	3,917	3,721
Exempt from federal income tax	303	255	612	499
Other investment income	234	196	450	375
Total interest income	14,379	15,159	29,029	28,974
INTEREST EXPENSE
Deposits	2,069	1,944	4,081	3,789
Short-term borrowings	296	115	547	209
Other borrowings	710	816	1,465	1,600
Total interest expense	3,075	2,875	6,093	5,598
NET INTEREST INCOME	11,304	12,284	22,936	23,376
Provision for loan losses	750	600	1,500	1,200
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	10,554	11,684	21,436	22,176
NONINTEREST INCOME
Service fees on deposit accounts	813	875	1,677	1,738
Services charges and fees on loans	273	297	627	577
Trust and investment fees	214	194	364	407
Gain on sale of investments		365		368
Earnings on Bank-owned life insurance	256	234	519	464
Insurance commissions	203	217	396	416
Other	25	95	58	124
Total noninterest income	1,784	2,277	3,641	4,094
NONINTEREST EXPENSE
Compensation and employee benefits	6,056	6,003	12,233	11,581
Occupancy and equipment	1,190	1,422	2,281	2,531
Professional fees	835	672	1,580	1,125
Data processing	931	1,079	1,865	1,998
Advertising	241	153	546	240
Federal Deposit Insurance Corporation (FDIC) premiums	213	322	400	600
(Gain) loss on foreclosed real estate	(5)	161	(101)	151
Merger related costs				245
Amortization of intangible assets	164	223	327	397
Other	879	1,071	1,775	2,024
Total noninterest expense	10,504	11,106	20,906	20,892
Income before income taxes	1,834	2,855	4,171	5,378
Income taxes	203	726	603	1,292
NET INCOME	$ 1,631	$ 2,129	$ 3,568	$ 4,086
Earnings per share
Basic	$ 0.15	$ 0.20	$ 0.34	$ 0.39
Diluted	0.15	0.20	0.34	0.39
Dividends per share	$ 0.09	$ 0.09	$ 0.18	$ 0.18

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 1,631	$ 2,129	$ 3,568	$ 4,086
Investment securities available for sale:
Unrealized holding gain (loss)	1,184	4,981	(9,048)	1,581
Tax effect	(403)	(1,694)	3,076	(538)
Reclassification of gains recognized in net income		(365)		(368)
Tax effect		124		125
Net of tax amount	781	3,046	(5,972)	800
Pension plan adjustment:
Pension plan curtailment	7,143		7,143
Tax effect	(2,429)		(2,429)
Reclassification adjustment related to actuarial losses	23	119	159	239
Tax effect	(10)	(40)	(56)	(81)
Net of tax amount	4,727	79	4,817	158
Derivative and hedging activities adjustments:
Changes in unrealized holding gains on derivative included in net income	40		1,092
Tax effect	(15)		(473)
Reclassification adjustment for gains on derivatives included in net income	(5)		6
Tax effect	3		(2)
Net of tax amount	23		623
Total other comprehensive income (loss)	5,531	3,125	(532)	958
Comprehensive income	$ 7,162	$ 5,254	$ 3,036	$ 5,044

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital [Member]	Unallocated Common Stock Held by the ESOP [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Sep. 30, 2015							$ (2,395)
Net income	$ 4,086
Other comprehensive loss	958						958
Ending Balance at Mar. 31, 2016							(1,437)
Beginning Balance at Dec. 31, 2015							(4,562)
Net income	2,129
Other comprehensive loss	3,125						3,125
Ending Balance at Mar. 31, 2016							(1,437)
Beginning Balance at Sep. 30, 2016	$ 176,344	$ 181	$ 181,900	$ (9,174)	$ 87,638	$ (82,369)	(1,832)
Beginning Balance, Shares at Sep. 30, 2016	11,393,558	11,393,558
Net income	$ 3,568				3,568
Other comprehensive loss	(532)						(532)
Cash dividends declared ($0.18 per share)	(1,907)				(1,907)
Stock based compensation	145		145
Allocation of ESOP stock	344		117	227
Allocation of treasury shares to incentive plan			(293)			293
Allocation of treasury shares to incentive plan, Shares		23,971
Stock options exercised	$ 807		(1,140)			1,947
Stock options exercised, Shares	488,491	157,300
Ending Balance at Mar. 31, 2017	$ 178,769	$ 181	180,729	(8,947)	89,299	(80,129)	(2,364)
Ending Balance, Shares at Mar. 31, 2017	11,574,829	11,574,829
Beginning Balance at Dec. 31, 2016							(7,895)
Net income	$ 1,631
Other comprehensive loss	5,531						5,531
Ending Balance at Mar. 31, 2017	$ 178,769	$ 181	$ 180,729	$ (8,947)	$ 89,299	$ (80,129)	$ (2,364)
Ending Balance, Shares at Mar. 31, 2017	11,574,829	11,574,829

Consolidated Statement of Chan7

Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (Parenthetical)	3 Months Ended
	Dec. 31, 2016$ / shares
Retained Earnings [Member]
Cash dividends declared, per share	$ 0.18

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING ACTIVITIES
Net income	$ 3,568	$ 4,086
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,500	1,200
Provision for depreciation and amortization	685	876
Amortization and accretion of discounts and premiums, net	2,216	1,750
Gain on sale of investment securities		(368)
Compensation expense on ESOP	344	303
Stock based compensation	145	79
Increase in accrued interest receivable	(160)	(477)
(Decrease) increase in accrued interest payable	(183)	146
Earnings on bank-owned life insurance	(519)	(464)
Deferred federal income taxes	170	166
Increase in accrued pension liability	297	590
(Gain) loss on foreclosed real estate	(101)	151
Amortization of intangible assets	327	397
Other, net	3,963	(222)
Net cash provided by operating activities	12,252	8,213
INVESTING ACTIVITIES
Certificates of deposit maturities	250	250
Investment securities available for sale:
Proceeds from sale of investment securities		29,022
Proceeds from principal repayments and maturities	33,192	47,903
Purchases	(48,049)	(50,016)
Decrease (increase) in loans receivable, net	5,792	(13,040)
Redemption of regulatory stock	11,413	6,940
Purchase of regulatory stock	(9,911)	(7,712)
Proceeds from sale of foreclosed real estate	1,557	739
Acquisition, net of cash acquired		(16,174)
Purchase of premises, equipment and software	(383)	(579)
Net cash used for investing activities	(6,139)	(2,667)
FINANCING ACTIVITIES
Increase (decrease) in deposits, net	23,555	(38,921)
Net (decrease) increase in short-term borrowings	(8,509)	34,904
Proceeds from other borrowings	17,597	52,300
Repayment of other borrowings	(49,030)	(50,800)
Increase in advances by borrowers for taxes and insurance	4,159	4,241
Purchase of treasury stock shares		(276)
Exercising of stock options	807
Dividends on common stock	(1,907)	(1,869)
Net cash used for financing activities	(13,328)	(421)
(Decrease) increase in cash and cash equivalents	(7,215)	5,125
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	43,658	18,758
CASH AND CASH EQUIVALENTS AT END OF PERIOD	36,443	23,883
Cash Paid:
Interest	6,276	5,388
Income taxes	(389)	500
Noncash items:
Transfers from loans to foreclosed real estate	2,112	726
Pension plan curtailment	7,143
Unrealized holding (loss) gain	$ (9,048)	1,581
Eagle National Bancorp, Inc [Member]
Noncash assets acquired:
Investment securities, available for sale		36,275
Loans receivable		123,380
Federal Home Loan Bank stock		889
Premises and equipment		945
Accrued interest receivable		185
Intangible assets		1,491
Goodwill		3,542
Deferred tax assets		715
Other assets		1,989
Liabilities assumed:
Certificates of deposit		32,408
Deposits other than certificates of deposit		119,865
Accrued interest payable		64
Other liabilities		900
Net noncash assets acquired		16,174
Cash acquired		$ 8,481

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	6 Months Ended
	Mar. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	1. Nature of Operations and Basis of Presentation The consolidated financial statements include the accounts of ESSA Bancorp, Inc. (the “Company”), its wholly owned subsidiary, ESSA Bank & Trust (the “Bank”), and the Bank’s wholly owned subsidiaries, ESSACOR Inc.; Pocono Investments Company; ESSA Advisory Services, LLC; Integrated Financial Corporation; and Integrated Abstract Incorporated, a wholly owned subsidiary of Integrated Financial Corporation. The primary purpose of the Company is to act as a holding company for the Bank. On November 6, 2014, the Company converted its status from a savings and loan holding company to a bank holding company. In addition, the Bank converted from a Pennsylvania-chartered savings association to a Pennsylvania-chartered savings bank. The Bank’s primary business consists of the taking of deposits and granting of loans to customers generally in Monroe, Northampton, Lehigh, Delaware, Chester, Montgomery, Lackawanna, and Luzerne Counties, Pennsylvania. The Bank is subject to regulation and supervision by the Pennsylvania Department of Banking and Securities and the Federal Deposit Insurance Corporation (the “FDIC”). The investment in subsidiary on the parent company’s financial statements is carried at the parent company’s equity in the underlying net assets. ESSACOR, Inc. is a Pennsylvania corporation that has been used to purchase properties at tax sales that represent collateral for delinquent loans of the Bank and is currently inactive. Pocono Investment Company is a Delaware corporation formed as an investment company subsidiary to hold and manage certain investments, including certain intellectual property. ESSA Advisory Services, LLC is a Pennsylvania limited liability company owned 100 percent by ESSA Bank & Trust. ESSA Advisory Services, LLC is a full-service insurance benefits consulting company offering group services such as health insurance, life insurance, short-term and long-term disability, dental, vision, and 401(k) retirement planning as well as individual health products. Integrated Financial Corporation is a Pennsylvania corporation that provided investment advisory services to the general public and is currently inactive. Integrated Abstract Incorporated is a Pennsylvania corporation that provided title insurance services and is currently inactive. All significant intercompany accounts and transactions have been eliminated in consolidation. The unaudited consolidated financial statements reflect all adjustments, which in the opinion of management, are necessary for a fair presentation of the results of the interim periods and are of a normal and recurring nature. Operating results for the three and six month periods ended March 31, 2017 are not necessarily indicative of the results that may be expected for the year ending September 30, 2017.

Earnings per Share

Earnings per Share	6 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings per Share	2. Earnings per Share The following table sets forth the composition of the weighted-average common shares (denominator) used in the basic and diluted earnings per share computation for the three and six month periods ended March 31, 2017 and 2016. Three Months Ended Six Months Ended March 31, March 31, March 31, March 31, 2017 2016 2017 2016 Weighted-average common shares outstanding 18,133,095 18,133,095 18,133,095 18,133,095 Average treasury stock shares (6,618,067 ) (6,793,799 ) (6,670,049 ) (6,793,553 ) Average unearned ESOP shares (888,285 ) (933,559 ) (894,004 ) (939,246 ) Average unearned non-vested shares (33,746 ) (20,584 ) (42,958 ) (24,681 ) Weighted average common shares and common stock equivalents used to calculate basic earnings per share 10,592,997 10,385,153 10,526,084 10,375,615 Additional common stock equivalents (non-vested stock) used to calculate diluted earnings per share 1,646 444 — — Additional common stock equivalents (stock options) used to calculate diluted earnings per share 97,317 139,100 91,157 140,155 Weighted average common shares and common stock equivalents used to calculate diluted earnings per share 10,691,960 10,524,697 10,617,241 10,515,770 At March 31, 2017 there were 53,371 shares of nonvested stock outstanding at an average weighted price of $11.77 per share that were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive. At March 31, 2016 there were 48,498 shares of nonvested stock outstanding at an average weighted price of $12.90 per share that were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive.

Use of Estimates in the Prepara

Use of Estimates in the Preparation of Financial Statements	6 Months Ended
	Mar. 31, 2017
Text Block [Abstract]
Use of Estimates in the Preparation of Financial Statements	3. Use of Estimates in the Preparation of Financial Statements The accounting principles followed by the Company and its subsidiaries and the methods of applying these principles conform to U.S. generally accepted accounting principles (“GAAP”) and to general practice within the banking industry. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the Consolidated Balance Sheet date and related revenues and expenses for the period. Actual results could differ from those estimates.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Mar. 31, 2017
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	4. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers Topic 606 In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In March 2016, the FASB issued ASU 2016-05, Derivatives and Hedging (Topic 815) . Topic 815 For public business entities, the amendments in this Update are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. For all other entities, the amendments in this Update are effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within fiscal years beginning after December 15, 2018. An entity has an option to apply the amendments in this Update on either a prospective basis or a modified retrospective basis. Early adoption is permitted, including adoption in an interim period. This Update is not expected to have a significant impact on the Company’s financial statements. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815) In March 2016, the FASB issued ASU 2016-07, Investments – Equity Method and Joint Ventures (Topic 323) In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606). Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Deferral of the Effective Date In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment To simplify the subsequent measurement of goodwill, the FASB eliminated Step 2 from the goodwill impairment test. In computing the implied fair value of goodwill under Step 2, an entity had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities (including unrecognized assets and liabilities) following the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. Instead, under the amendments in this Update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting units fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. A public business entity that is a U.S. Securities and Exchange Commission (“SEC”) filer should adopt the amendments in this Update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. A public business entity that is not an SEC filer should adopt the amendments in this Update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2020. All other entities, including not-for-profit entities, that are adopting the amendments in this Update should do so for their annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2021. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations. In February 2017, the FASB issued ASU 2017-05, Other Income — Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) The amendments in this Update clarify what constitutes a financial asset within the scope of Subtopic 610-20. The amendments also clarify that entities should identify each distinct nonfinancial asset or in substance nonfinancial asset that is promised to a counterparty and to derecognize each asset when the counterparty obtains control. There is also additional guidance provided for partial sales of a nonfinancial asset and when derecognition, and the related gain or loss, should be recognized. The amendments in this Update are effective at the same time as the amendments in Update 2014-09. Therefore, for public entities, the amendments are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. For all other entities, the amendments in this Update are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations. In February 2017, the FASB issued ASU 2017-06 , Plan Accounting: Defined Benefit Pension Plans (Topic 960), Defined Contribution Pension Plans (Topic 962), and Health and Welfare Benefit Plans (Topic 965) This Update relates primarily to the reporting by an employee benefit plan for its interest in a master trust, which is a trust for which a regulated financial institution serves as a trustee or custodian and in which assets of more than one plan sponsored by a single employer or by a group of employers under common control are held. For each master trust in which a plan holds an interest, the amendments in this Update require a plan's interest in that master trust and any change in that interest to be presented in separate line items in the statement of net assets available for benefits and in the statement of changes in net assets available for benefits, respectively. The amendments in this Update remove the requirement to disclose the percentage interest in the master trust for plans with divided interests and require that all plans disclose the dollar amount of their interest in each of those general types of investments, which supplements the existing requirement to disclose the master trusts balances in each general type of investments. There are also increased disclosure requirements for investments in master trusts. The amendments in this Update are effective for fiscal years beginning after December 15, 2018. Early adoption is permitted. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations. In March 2017, the FASB issued ASU 2017-07, Compensation — Retirement Benefits (Topic 715) The amendments in this Update require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost as defined in paragraphs 715-30-35-4 and 715-60-35-9 are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. If a separate line item or items are used to present the other components of net benefit cost, that line item or items must be appropriately described. If a separate line item or items are not used, the line item or items used in the income statement to present the other components of net benefit cost must be disclosed. For public business entities, the amendments in this Update are effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. For all other entities, the amendments in the Update are effective for annual periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of an annual period for which financial statements (interim or annual) have not been issued or made available for issuance. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations. In March 2017, the FASB issued ASU 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20).

Investment Securities

Investment Securities	6 Months Ended
	Mar. 31, 2017
Investments Debt And Equity Securities [Abstract]
Investment Securities	5. The amortized cost, gross unrealized gains and losses, and fair value of investment securities available for sale are summarized as follows (in thousands): March 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 120,437 $ 244 $ (1,591 ) $ 119,090 Freddie Mac 95,669 73 (1,136 ) 94,606 Governmental National Mortgage Association 14,610 34 (218 ) 14,426 Total mortgage-backed securities 230,716 351 (2,945 ) 228,122 Obligations of states and political subdivisions 68,995 1,314 (974 ) 69,335 U.S. government agency securities 23,344 119 — 23,463 Corporate obligations 45,315 203 (738 ) 44,780 Other debt securities 29,980 122 (512 ) 29,590 Total debt securities 398,350 2,109 (5,169 ) 395,290 Equity securities - financial services 25 — — 25 Total $ 398,375 $ 2,109 $ (5,169 ) $ 395,315 September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 115,535 $ 1,891 $ (173 ) $ 117,253 Freddie Mac 84,486 1,369 (85 ) 85,770 Governmental National Mortgage Association 16,091 76 (28 ) 16,139 Total mortgage-backed securities 216,112 3,336 (286 ) 219,162 Obligations of states and political subdivisions 71,323 2,432 (65 ) 73,690 U.S. government agency securities 25,669 272 — 25,941 Corporate obligations 38,331 599 (512 ) 38,418 Other debt securities 32,962 428 (216 ) 33,174 Total debt securities 384,397 7,067 (1,079 ) 390,385 Equity securities - financial services 25 — — 25 Total $ 384,422 $ 7,067 $ (1,079 ) $ 390,410 The amortized cost and fair value of debt securities at March 31, 2017, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties (in thousands): Available For Sale Amortized Cost Fair Value Due in one year or less $ 15,986 $ 16,013 Due after one year through five years 35,680 35,666 Due after five years through ten years 92,538 92,271 Due after ten years 254,146 251,340 Total $ 398,350 $ 395,290 For the three and six months ended March 31, 2017, the Company realized no gross gains or gross losses on proceeds from the sale of investment securities. For the three months ended March 31, 2016, the Company realized gross gains of $365,000 and no gross losses on proceeds from the sale of investment securities of $17.4 million. For the six months ended March 31, 2016, the Company realized gross gains of $368,000 on proceeds from the sale of investment securities of $29.0 million. During the first quarter of fiscal 2016, the Company sold $16.2 million of investment securities which were acquired in the merger with Eagle National Bancorp, Inc (“ENB”). The Company realized no gain or loss from the sale of these securities. The following table shows the Company’s gross unrealized losses and fair value, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position (dollars in thousands): March 31, 2017 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 61 $ 76,418 $ (1,192 ) $ 11,033 $ (399 ) $ 87,451 $ (1,591 ) Freddie Mac 50 66,922 (909 ) 6,701 (227 ) 73,623 (1,136 ) Governmental National Mortgage Association 9 7,292 (181 ) 2,373 (37 ) 9,665 (218 ) Obligations of states and political subdivisions 29 34,982 (974 ) — — 34,982 (974 ) Corporate obligations 23 18,850 (437 ) 6,198 (301 ) 25,048 (738 ) Other debt securities 18 12,303 (338 ) 8,804 (174 ) 21,107 (512 ) Total 190 $ 216,767 $ (4,031 ) $ 35,109 $ (1,138 ) $ 251,876 $ (5,169 ) September 30, 2016 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 17 $ 6,841 $ (21 ) $ 12,261 $ (152 ) $ 19,102 $ (173 ) Freddie Mac 11 7,457 (11 ) 6,375 (74 ) 13,832 (85 ) Governmental National Mortgage Association 5 4,704 (16 ) 1,267 (12 ) 5,971 (28 ) Obligations of states and political subdivisions 12 14,420 (65 ) — — 14,420 (65 ) Corporate obligations 12 8,778 (172 ) 5,303 (340 ) 14,081 (512 ) Other debt securities 13 6,582 (126 ) 6,914 (90 ) 13,496 (216 ) Total 70 $ 48,782 $ (411 ) $ 32,120 $ (668 ) $ 80,902 $ (1,079 ) The Company’s investment securities portfolio contains unrealized losses on securities, including mortgage-related instruments issued or backed by the full faith and credit of the United States government, or generally viewed as having the implied guarantee of the U.S. government, other mortgage backed securities, debt obligations of a U.S. state or political subdivision and corporate debt obligations. The Company reviews its position quarterly and has asserted that at March 31, 2017, the declines outlined in the above table represent temporary declines and the Company would not be required to sell the above securities before their anticipated recovery in market value. The Company has concluded that any impairment of its investment securities portfolio is not other than temporary but is the result of interest rate changes that are not expected to result in the non-collection of principal and interest during the period.

Loans Receivable, Net and Allow

Loans Receivable, Net and Allowance for Loan Losses	6 Months Ended
	Mar. 31, 2017
Receivables [Abstract]
Loans Receivable, Net and Allowance for Loan Losses	6. Loans Receivable, Net and Allowance for Loan Losses Loans receivable consist of the following (in thousands): March 31, 2017 September 30, 2016 Real estate loans: Residential $ 592,169 $ 596,645 Construction 3,928 1,733 Commercial 290,411 288,447 Commercial 34,125 39,978 Obligations of states and political subdivisions 61,746 56,923 Home equity loans and lines of credit 45,651 48,163 Auto Loans 186,697 193,078 Other 3,136 3,302 1,217,863 1,228,269 Less allowance for loan losses 9,366 9,056 Net loans $ 1,208,497 $ 1,219,213 Purchased loans acquired in a business combination are recorded at fair value on their purchase date without a carryover of the related allowance for loan losses. Upon acquisition, the Company evaluates whether each acquired loan (regardless of size) is within the scope of ASC 310-30, Receivables-Loans and Debt Securities Acquired with Deteriorated Credit Quality On the acquisition date, the preliminary estimate of the unpaid principal balance for all loans evidencing credit impairment acquired in the ENB acquisition was $3.5 million and the estimated fair value of the loans was $2.0 million. Total contractually required payments on these loans, including interest, at the acquisition date was $4.2 million. However, the Company’s preliminary estimate of expected cash flows was $2.2 million. At such date, the Company established a credit risk related non-accretable discount (a discount representing amounts which are not expected to be collected from the customer nor liquidation of collateral) of $2.0 million relating to these impaired loans, reflected in the recorded net fair value. Such amount is reflected as a non-accretable fair value adjustment to loans. The Company further estimated the timing and amount of expected cash flows in excess of the estimated fair value and established an accretable discount of $240,000 on the acquisition date relating to these impaired loans. The carrying value of the loans acquired and accounted for in accordance with ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality Unpaid principal balance $ 3,468 Interest 717 Contractual cash flows 4,185 Non-accretable discount (1,973 ) Expected cash flows 2,212 Accretable discount (240 ) Estimated fair value $ 1,972 Changes in the accretable yield for purchased credit-impaired loans were as follows, since acquisition, for the three and six month periods ended March 31, 2017 and March 31, 2016 (in thousands): Three Months Ended March 31, 2017 2016 Balance at beginning of period $ 453 $ 448 Reclassification, new additions and other 82 — Accretion (75 ) (83 ) Balance at end of period $ 460 $ 365 Six Months Ended March 31, 2017 2016 Balance at beginning of period $ 478 $ 258 Reclassification, new additions and other 118 240 Accretion (136 ) (133 ) Balance at end of period $ 460 $ 365 The following table presents additional information regarding loans acquired and accounted for in accordance with ASC 310-30 (in thousands): March 31, 2017 September 30, 2016 Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Outstanding balance $ 6,309 $ 6,893 Carrying amount $ 5,098 $ 5,563 The following tables show the amount of loans in each category that was individually and collectively evaluated for impairment at the dates indicated (in thousands): Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment March 31, 2017 Real estate loans: Residential $ 592,169 $ 7,011 $ — $ 585,158 Construction 3,928 — — 3,928 Commercial 290,411 10,542 4,453 275,416 Commercial 34,125 1,742 321 32,062 Obligations of states and political subdivisions 61,746 — — 61,746 Home equity loans and lines of credit 45,651 216 324 45,111 Auto loans 186,697 780 — 185,917 Other 3,136 24 — 3,112 Total $ 1,217,863 $ 20,315 $ 5,098 $ 1,192,450 Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment September 30, 2016 Real estate loans: Residential $ 596,645 $ 8,721 $ — $ 587,924 Construction 1,733 — — 1,733 Commercial 288,447 11,237 4,615 272,595 Commercial 39,978 1,698 411 37,869 Obligations of states and political sub divisions 56,923 — — 56,923 Home equity loans and lines of credit 48,163 361 537 47,265 Auto loans 193,078 526 — 192,552 Other 3,302 22 — 3,280 Total $ 1,228,269 $ 22,565 $ 5,563 $ 1,200,141 The Company maintains a loan review system that allows for a periodic review of our loan portfolio and the early identification of potential impaired loans. Such system takes into consideration, among other things, delinquency status, size of loans, type and market value of collateral and financial condition of the borrowers. Specific loan loss allowances are established for identified losses based on a review of such information. A loan evaluated for impairment is considered to be impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement. All loans identified as impaired are evaluated independently. The Company does not aggregate such loans for evaluation purposes. Impairment is measured on a loan-by-loan basis for commercial and construction loans by the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral-dependent. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not separately identify individual consumer and residential mortgage loans for impairment disclosures, unless such loans are part of a larger relationship that is impaired, or are classified as a troubled debt restructuring. A loan is considered to be a troubled debt restructuring (“TDR”) loan when the Company grants a concession to the borrower that it would not otherwise consider because of the borrower’s financial condition. Such concessions include the reduction of interest rates, forgiveness of principal or interest, or other modifications of interest rates that are less than the current market rate for new obligations with similar risk. TDR loans that are in compliance with their modified terms and that yield a market rate at the time of modification may be removed from TDR status after one year of performance. The following tables include the recorded investment and unpaid principal balances for impaired loans with the associated allowance amount at the dates indicated, if applicable (in thousands): Recorded Investment Unpaid Principal Balance Associated Allowance March 31, 2017 With no specific allowance recorded: Real estate loans Residential $ 5,351 $ 7,155 $ — Construction — — — Commercial 10,422 11,569 — Commercial 1,557 1,627 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 211 287 — Auto loans 208 290 — Other 24 29 — Total 17,773 20,957 — With an allowance recorded: Real estate loans Residential 1,660 1,990 128 Construction — — — Commercial 120 128 26 Commercial 185 199 125 Obligations of states and political subdivisions — — — Home equity loans and lines of credit 5 5 5 Auto loans 572 575 201 Other — — — Total 2,542 2,897 485 Total: Real estate loans Residential 7,011 9,145 128 Construction — — — Commercial 10,542 11,697 26 Commercial 1,742 1,826 125 Obligations of states and political subdivisions — — — Home equity loans and lines of credit 216 292 5 Auto loans 780 865 201 Other 24 29 — Total Impaired Loans $ 20,315 $ 23,854 $ 485 Recorded Investment Unpaid Principal Balance Associated Allowance September 30, 2016 With no specific allowance recorded: Real Estate Loans Residential $ 6,721 $ 9,016 $ — Construction — — — Commercial 10,939 12,928 — Commercial 1,698 1,725 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 361 432 — Auto Loans 253 365 — Other 22 22 — Total 19,994 24,488 — With an allowance recorded: Real Estate Loans Residential 2,000 2,151 198 Construction — — — Commercial 298 303 36 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto Loans 273 273 113 Other — — — Total 2,571 2,727 347 Total: Real Estate Loans Residential 8,721 11,167 198 Construction — — — Commercial 11,237 13,231 36 Commercial 1,698 1,725 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 361 432 — Auto Loans 526 638 113 Other 22 22 — Total Impaired Loans $ 22,565 $ 27,215 $ 347 The following tables represent the average recorded investments in the impaired loans and the related amount of interest recognized during the time within the period that the impaired loans were impaired (in thousands): For the Three Months Ended March 31, 2017 2016 2017 2016 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 5,573 $ 7,296 $ 9 $ 22 Construction — — — — Commercial 9,218 12,128 67 131 Commercial 1,637 1,919 29 37 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 202 594 — — Auto loans 102 228 — — Other 8 — — — Total 16,740 22,165 105 190 With an allowance recorded: Real estate loans Residential 1,985 2,679 — 4 Construction — — — — Commercial 341 1,490 — — Commercial 100 6 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 5 59 — — Auto loans 291 222 2 2 Other — 1 — — Total 2,722 4,457 2 6 Total: Real estate loans Residential 7,558 9,975 9 26 Construction — — — — Commercial 9,559 13,618 67 131 Commercial 1,737 1,925 29 37 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 207 653 — — Auto loans 393 450 2 2 Other 8 1 — — Total Impaired Loans $ 19,462 $ 26,622 $ 107 $ 196 For the Six Months Ended March 31, 2017 2016 2017 2016 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 6,049 $ 8,040 $ 21 $ 48 Construction — — — — Commercial 9,890 12,908 172 307 Commercial 1,665 1,350 62 52 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 260 672 — 2 Auto loans 119 255 — 2 Other 8 — — — Total 17,991 23,225 255 411 With an allowance recorded: Real estate loans Residential 2,025 2,636 — 9 Construction — — — — Commercial 345 974 — — Commercial 59 4 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 4 66 — — Auto loans 253 181 6 3 Other — — — — Total 2,686 3,861 6 12 Total: Real estate loans Residential 8,074 10,676 21 57 Construction — — — — Commercial 10,235 13,882 172 307 Commercial 1,724 1,354 62 52 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 264 738 — 2 Auto loans 372 436 6 5 Other 8 — — — Total Impaired Loans $ 20,677 $ 27,086 $ 261 $ 423 The Company uses a ten-point internal risk-rating system to monitor the credit quality of the overall loan portfolio. The first six categories are considered not criticized and are aggregated as Pass-rated. The criticized rating categories utilized by management generally follow bank regulatory definitions. The Special Mention category includes assets that are fundamentally sound yet exhibit potentially unacceptable credit risk or deteriorating trends or characteristics which, if left uncorrected, may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. Loans in the Substandard category have well-defined weaknesses that jeopardize the liquidation of the debt and have a distinct possibility that some loss will be sustained if the weaknesses are not corrected. All loans more than 90 days past due are considered Substandard. Loans in the Doubtful category have all the weaknesses inherent in loans classified as Substandard with the added characteristic that their weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. Loans in the Loss category are considered uncollectible and of little value that their continuance as bankable assets is not warranted. Certain residential real estate loans, construction loans, home equity loans and lines of credit, auto loans and other consumer loans are underwritten and structured using standardized criteria and characteristics, primarily payment performance, and are normally risk rated and monitored collectively on a monthly basis. These are typically loans to individuals in the consumer categories and are delineated as either performing or non-performing. To help ensure that risk ratings are accurate and reflect the present and future capacity of borrowers to repay a loan as agreed, the Bank has a structured loan rating process with several layers of internal and external oversight. Generally, consumer and residential mortgage loans are included in the Pass categories unless a specific action, such as bankruptcy, repossession, or death occurs to raise awareness of a possible credit event. The Bank’s Commercial Loan Officers are responsible for the timely and accurate risk rating recommendation for the loans in their portfolios at origination and on an ongoing basis. The Bank’s Commercial Loan Officers perform an annual review of all commercial relationships $750,000 or greater. Confirmation of the appropriate risk grade is included in the review on an ongoing basis. The Bank engages an external consultant to conduct loan reviews on at least a semi-annual basis. Generally, the external consultant reviews commercial relationships greater than $1,000,000 and/or all criticized relationships. Detailed reviews, including plans for resolution, are performed on loans classified as Substandard on a quarterly basis. Loans in the Special Mention and Substandard categories that are collectively evaluated for impairment are given separate consideration in the determination of the allowance. The following tables present the classes of the loan portfolio summarized by the aggregate Pass and the criticized categories of Special Mention, Substandard, and Doubtful or Loss within the internal risk rating system at March 31, 2017 and September 30, 2016 (in thousands): Pass Special Mention Substandard Doubtful or Loss Total March 31, 2017 Commercial real estate loans $ 266,868 $ 5,225 $ 18,318 $ — $ 290,411 Commercial 30,657 177 3,291 — 34,125 Obligations of states and political subdivisions 61,746 — — — 61,746 Total $ 359,271 $ 5,402 $ 21,609 $ — $ 386,282 Pass Special Mention Substandard Doubtful or Loss Total September 30, 2016 Commercial real estate loans $ 260,088 $ 8,886 $ 19,473 $ — $ 288,447 Commercial 36,684 180 3,114 — 39,978 Obligations of states and political subdivisions 56,923 — — — 56,923 Total $ 353,695 $ 9,066 $ 22,587 $ — $ 385,348 All other loans are underwritten and structured using standardized criteria and characteristics, primarily payment performance, and are normally risk rated and monitored collectively on a monthly basis. These are typically loans to individuals in the consumer categories and are delineated as either performing or non-performing. The following tables present the risk ratings in the consumer categories of performing and non-performing loans at March 31, 2017 and September 30, 2016 (in thousands): Performing Non- performing Purchased Credit Impaired Total March 31, 2017 Real estate loans: Residential $ 584,544 $ 7,625 $ — $ 592,169 Construction 3,928 — — 3,928 Home equity loans and lines of credit 45,053 274 324 45,651 Auto loans 185,907 790 — 186,697 Other 3,102 34 — 3,136 Total $ 822,534 $ 8,723 $ 324 $ 831,581 Performing Non- performing Purchased Impaired Credit Total September 30, 2016 Real estate loans: Residential $ 587,673 $ 8,972 $ — $ 596,645 Construction 1,733 — — 1,733 Home equity loans and lines of credit 47,213 413 537 48,163 Auto loans 192,734 344 — 193,078 Other 3,271 31 — 3,302 Total $ 832,624 $ 9,760 $ 537 $ 842,921 The Company further monitors the performance and credit quality of the loan portfolio by analyzing the age of the portfolio as determined by the length of time a recorded payment is past due. The following tables present the classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans as of March 31, 2017 and September 30, 2016 (in thousands): Current 31-60 Days Past Due 61-90 Days Past Due Greater than 90 Days Past Due and still accruing Non-Accrual Total Past Due and Non- Accrual Purchased Credit Impaired Total Loans March 31, 2017 Real estate loans Residential $ 582,864 $ 1,081 $ 599 $ — $ 7,625 $ 9,305 $ — $ 592,169 Construction 3,928 — — — — — — 3,928 Commercial 282,390 284 — — 3,284 3,568 4,453 290,411 Commercial 32,994 80 — — 730 810 321 34,125 Obligations of states and political subdivisions 61,746 — — — — — — 61,746 Home equity loans and lines of credit 45,027 18 8 — 274 300 324 45,651 Auto loans 185,398 427 82 — 790 1,299 — 186,697 Other 3,054 48 — — 34 82 — 3,136 Total $ 1,197,401 $ 1,938 $ 689 $ — $ 12,737 $ 15,364 $ 5,098 $ 1,217,863 Current 31-60 Days Past Due 61-90 Days Past Due Greater than 90 Days Past Due and still accruing Non-Accrual Total Past Due and Non- Accrual Purchased Credit Impaired Total Loans September 30, 2016 Real estate loans Residential $ 585,517 $ 1,496 $ 660 $ — $ 8,972 $ 11,128 $ — $ 596,645 Construction 1,733 — — — — — — 1,733 Commercial 279,019 1,093 191 — 3,529 4,813 4,615 288,447 Commercial 38,862 185 57 — 463 705 411 39,978 Obligations of states and political subdivisions 56,923 — — — — — — 56,923 Home equity loans and lines of credit 47,026 40 147 — 413 600 537 48,163 Auto loans 191,785 717 232 — 344 1,293 — 193,078 Other 3,264 7 — — 31 38 — 3,302 Total $ 1,204,129 $ 3,538 $ 1,287 $ — $ 13,752 $ 18,577 $ 5,563 $ 1,228,269 The allowance for loan losses is maintained at a level necessary to absorb loan losses that are both probable and reasonably estimable. Management, in determining the allowance for loan losses, considers the losses inherent in its loan portfolio and changes in the nature and volume of loan activities, along with the general economic and real estate market conditions. The allowance for loan losses consists of two elements: (1) an allocated allowance, which comprises allowances established on specific loans and class allowances based on historical loss experience and current trends, and (2) an allocated allowance based on general economic conditions and other risk factors in our markets and portfolios. We maintain a loan review system, which allows for a periodic review of our loan portfolio and the early identification of potential impaired loans. Such system takes into consideration, among other things, delinquency status, size of loans, type and market value of collateral and financial condition of the borrowers. General loan loss allowances are based upon a combination of factors including, but not limited to, actual loan loss experience, composition of the loan portfolio, current economic conditions, management’s judgment and losses which are probable and reasonably estimable. The allowance is increased through provisions charged against current earnings and recoveries of previously charged-off loans. Loans that are determined to be uncollectible are charged against the allowance. While management uses available information to recognize probable and reasonably estimable loan losses, future loss provisions may be necessary, based on changing economic conditions. Payments received on impaired loans generally are either applied against principal or reported as interest income, according to management’s judgment as to the collectability of principal. The allowance for loan losses as of March 31, 2017 was maintained at a level that represents management’s best estimate of losses inherent in the loan portfolio, and such losses were both probable and reasonably estimable. In addition, the FDIC and the Pennsylvania Department of Banking and Securities, as an integral part of their examination process, have periodically reviewed our allowance for loan losses. The banking regulators may require that we recognize additions to the allowance based on its analysis and review of information available to it at the time of its examination. Management reviews the loan portfolio on a quarterly basis using a defined, consistently applied process in order to make appropriate and timely adjustments to the allowance for loan losses (“ALL”). When information confirms all or part of specific loans to be uncollectible, these amounts are promptly charged off against the ALL. The following tables summarize changes in the primary segments of the ALL for the three and six month periods ending March 31, 2017 and 2016 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total ALL balance at December 31, 2016 $ 4,450 $ 23 $ 795 $ 965 $ 234 $ 441 $ 2,062 $ 25 $ 347 $ 9,342 Charge-offs (290 ) — (128 ) (1 ) — (6 ) (544 ) — — (969 ) Recoveries 5 — — — — 2 232 4 — 243 Provision (35 ) 7 371 (13 ) 10 8 158 (5 ) 249 750 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 ALL balance at December 31, 2015 $ 4,747 $ 14 $ 858 $ 705 $ 187 $ 389 $ 1,754 $ 27 $ 576 $ 9,257 Charge-offs (308 ) — (9 ) — — (29 ) (234 ) — — (580 ) Recoveries — — 52 — — 3 80 3 — 138 Provision 216 10 67 33 9 26 325 (5 ) (81 ) 600 ALL balance at March 31, 2016 $ 4,655 $ 24 $ 968 $ 738 $ 196 $ 389 $ 1,925 $ 25 $ 495 $ 9,415 ALL balance at September 30, 2016 $ 4,426 $ 13 $ 852 $ 882 $ 215 $ 455 $ 1,880 $ 25 $ 308 $ 9,056 Charge-offs (366 ) — (218 ) (20 ) — (6 ) (1,061 ) (4 ) — (1,675 ) Recoveries 6 — 10 — — 3 460 6 — 485 Provision 64 17 394 89 29 (7 ) 629 (3 ) 288 1,500 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 ALL balance at September 30, 2015 $ 5,140 $ 7 $ 671 $ 693 $ 189 $ 461 $ 1,570 $ 27 $ 161 $ 8,919 Charge-offs (399 ) — (9 ) (3 ) — (54 ) (422 ) — — (887 ) Recoveries 3 — 52 1 — 4 117 6 — 183 Provision (89 ) 17 254 47 7 (22 ) 660 (8 ) 334 1,200 ALL balance at March 31, 2016 $ 4,655 $ 24 $ 968 $ 738 $ 196 $ 389 $ 1,925 $ 25 $ 495 $ 9,415 Acquired loans are recorded at fair value on their purchase date without a carryover of the related allowance for loan losses. The following table summarizes the primary segments of the ALL, segregated into two categories, the amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment as of March 31, 2017 and September 30, 2016 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total Individually evaluated for impairment $ 128 $ — $ 26 $ 125 $ — $ 5 $ 201 $ — $ — $ 485 Collectively evaluated for impairment 4,002 30 1,012 826 244 440 1,707 24 596 8,881 ALL Balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 Individually evaluated for impairment $ 198 $ — $ 36 $ — $ — $ — $ 113 $ — $ — $ 347 Collectively evaluated for impairment 4,228 13 816 882 215 455 1,767 25 308 8,709 ALL balance at September 30, 2016 $ 4,426 $ 13 $ 852 $ 882 $ 215 $ 455 $ 1,880 $ 25 $ 308 $ 9,056 The allowance for loan losses is based on estimates, and actual losses will vary from current estimates. Management believes that the granularity of the homogeneous pools and the related historical loss ratios and other qualitative factors, as well as the consistency in the application of assumptions, result in an ALL that is representative of the risk found in the components of the portfolio at any given date. Despite the above allocations, the allowance for loan losses is general in nature and is available to absorb losses from any loan segment. The following is a summary of troubled debt restructuring granted during the three months ended March 31, 2017 and 2016 (dollars in thousands): For the Three Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 1 $ 135 $ 135 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 3 $ 291 $ 291 For the Three Months Ended March 31, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 3 $ 587 $ 587 Construction — — — Commercial 1 77 77 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other — — — Total 4 $ 664 $ 664 The following is a summary of troubled debt restructuring granted during the six months ended March 31, 2017 and 2016 (dollars in thousands): For the Six Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 3 $ 379 $ 379 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 5 $ 535 $ 535 For the Six Months Ended March 31, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 4 $ 668 $ 668 Construction — — — Commercial 1 77 77 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other — — — Total 5 $ 745 $ 745 Of the three new troubled debt restructurings granted for the three months ended March 31, 2017, one loan for $135,000 was granted terms concessions, one loan for $132,000 was granted terms and rate concessions, and one loan for $24,000 was granted interest rate concessions. Of the four new troubled debt restructurings granted for the three months ended March 31, 2016, two loans totaling $572,000, were granted terms and rate concessions, one loan totaling $15,000 was granted term concessions and one loan totaling $77,000 was granted a rate concession. Of the five new troubled debt restructurings granted for the six months ended March 31, 2017, one loan totaling $135,000 was granted terms concessions, one loan totaling $24,000 was granted interest rate concessions, and three loans totaling $376,000 were granted terms and rate concessions. Of the five new troubled debt restructurings granted for the six months ended March 31, 2016, two loans totaling $572,000 were granted term and rate concessions, two loans totaling $96,000 were granted term concessions and one loan totaling $77,000 was granted a rate concession. For the three months ended March 31, 2017 no loans defaulted on a restructuring agreement within one year of modification. For the six months ended March 31, 2017, one loan totaling $107,000 defaulted on a restructuring agreement within one year of modification. For the three and six months ended March 31, 2016, no loans defaulted on a restructuring agreement within one year of modification. Foreclosed assets acquired in settlement of loans are carried at fair value, less estimated costs to sell, and are included in the Consolidated Balance Sheet. As of March 31, 2017 and September 30, 2016, included with other assets are $3.3 million and $2.7 million, of foreclosed assets, respectively. As of March 31, 2017, included within the foreclosed assets is $2.1 million of consumer residential mortgages that were foreclosed on or received via a deed in lieu transaction prior to the period end. As of March 31, 2017, the Company has initiated formal foreclosure proceedings on $2.2 million of consumer residential mortgages which have not yet been transferred into foreclosed assets.

Deposits

Deposits	6 Months Ended
	Mar. 31, 2017
Banking And Thrift [Abstract]
Deposits	7. Deposits Deposits consist of the following major classifications (in thousands): March 31, 2017 September 30, 2016 Non-interest bearing demand accounts $ 150,762 $ 142,924 Interest bearing demand accounts 139,528 167,259 Money market accounts 255,502 249,947 Savings and club accounts 145,478 142,021 Certificates of deposit 547,105 512,669 Total $ 1,238,375 $ 1,214,820

Net Periodic Benefit Cost-Defin

Net Periodic Benefit Cost-Defined Benefit Plan	6 Months Ended
	Mar. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Net Periodic Benefit Cost-Defined Benefit Plan	8 . Net Periodic Benefit Cost-Defined Benefit Plan For a detailed disclosure on the Bank’s pension and employee benefits plans, please refer to Note 12 of the Company’s Consolidated Financial Statements for the year ended September 30, 2016 included in the Company’s Annual Report on Form 10-K. The following table comprises the components of net periodic benefit cost for the three and six month periods ended March 31, 2017 and 2016 (in thousands): For the Three Months Ended March 31, For the Six Months Ended March 31, 2017 2016 2017 2016 Service Cost $ 69 $ 249 $ 378 $ 498 Interest Cost 208 245 443 490 Expected return on plan assets (348 ) (311 ) (689 ) (622 ) Amortization of unrecognized loss 23 119 159 239 Net periodic benefit cost $ (48 ) $ 302 $ 291 $ 605 The Company’s board of directors adopted resolutions to freeze the status of the Defined Benefit Plan (“the plan”) effective February 28, 2017. (“the freeze date”). Accordingly, no additional participants will enter the plan after February 28, 2017; no additional years of service for benefit accrual purposes will be credited after the freeze date under the plan; and compensation earned by participants after the freeze date will not be taken into account under the plan. As a result of the freeze, the Company’s projected benefit obligation decreased by $7.1 million and there was a tax effected $4.7 million increase to accumulated other comprehensive income in the quarter ended March 31, 2017.

Equity Incentive Plan

Equity Incentive Plan	6 Months Ended
	Mar. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plan	9 . Equity Incentive Plan The Company previously maintained the ESSA Bancorp, Inc. 2007 Equity Incentive Plan (the “Plan”). The Plan provided for a total of 2,377,326 shares of common stock for issuance upon the grant or exercise of awards. Of the shares that were available under the Plan, 1,698,090 were available to be issued in connection with the exercise of stock options and 679,236 were available to be issued as restricted stock. The Plan allowed for the granting of non-qualified stock options (“NSOs”), incentive stock options (“ISOs”), and restricted stock. Options granted under the plan were granted at no less than the fair value of the Company’s common stock on the date of the grant. As of the effective date of the 2016 Equity Incentive Plan (detailed below), no further grants will be made under the Plan and forfeitures of outstanding awards under the Plan will be added to the shares available under the 2016 Equity Incentive Plan. The Company replaced the 2007 Equity Incentive Plan with the ESSA Bancorp, Inc. 2016 Equity Incentive Plan (the “2016 Plan”) which was approved by shareholders on March 3, 2016. The 2016 Plan provides for a total of 250,000 shares of common stock for issuance upon the grant or exercise of awards. The 2016 Plan allows for the granting of restricted stock, restricted stock units, ISOs and NSOs. Certain officers, employees and outside directors were granted in aggregate 1,140,469 NSOs; 317,910 ISOs; and 590,320 shares of restricted stock on May 23, 2008. Certain officers were granted in aggregate 30,000 shares of restricted stock on April 1, 2013, 19,880 shares of restricted stock on July 22, 2014, 21,843 shares of restricted stock on May 20, 2015, 23,491 shares of restricted stock on March 4, 2016, 20,675 shares of restricted stock on December 13, 2016 and 3,296 shares of restricted stock on March 29, 2017. In accordance with generally accepted accounting principles, the Company expenses the fair value of all share-based compensation grants over the requisite service periods. The Company classifies share-based compensation for employees and outside directors within “Compensation and employee benefits” in the Consolidated Statement of Income to correspond with the same line item as compensation paid. Stock options vest over a five-year service period and expire ten years after the grant date. The Company recognizes compensation expense for the fair values of these awards, which vest on a straight-line basis over the requisite service period of the awards. The 2013 restricted stock shares vested over an 18 month service period. The 2014 restricted shares vest over a 39 month service period. The 2015 restricted shares vest over a 40 month service period. The March 4, 2016 restricted shares vest over a 43 month service period. The December 13, 2016 restricted shares vest over a 46 month service period. The March 29, 2017 restricted shares vest over 42 months for 1,296 shares and over 18 months for 2,000 shares. The product of the number of shares granted and the grant date market price of the Company’s common stock determines the fair value of restricted shares under the Company’s restricted stock plan. For the six months ended March 31, 2017 and 2016, the Company recorded $145,000 and $79,000 of share-based compensation expense, respectively, comprised of restricted stock expense. Expected future compensation expense relating to the restricted shares issued in 2014, at March 31, 2017 is $32,000 over the remaining vesting period of 0.5 years. Expected future compensation expense relating to the restricted shares issued in 2015, at March 31, 2017 is $123,000 over the remaining vesting period of 1.5 years. Expected future compensation expense relating to the restricted shares issued in March 2016, at March 31, 2017 is $213,000 over the remaining vesting period of 2.5 years. Expected future compensation expense relating to the restricted shares issued in December 2016, at March 31, 2017 is $313,000 over the remaining vesting period of 3.5 years. Expected future compensation expense relating to the restricted shares (1,296) issued in March 2017, at March 31, 2017 is $19,000 over the remaining vesting period of 3.5 years. Expected future compensation expense relating to the restricted shares (2,000) issued in March 2017, at March 31, 2017 is $29,000 over the remaining vesting period of 1.5 years. The following is a summary of the Company’s stock option activity and related information for its option grants for the six month period ended March 31, 2017. Number of Stock Options Weighted- average Exercise Price Weighted- average Remaining Contractual Term (in Aggregate Intrinsic Value (in thousands) Outstanding, September 30, 2016 905,987 $ 12.35 1.67 $ 1,341 Granted — — — — Exercised 488,491 12.35 1.17 — Forfeited — — — — Outstanding, March 31, 2017 417,496 $ 12.35 1.17 $ 932 Exercisable at March 31, 2017 417,496 $ 12.35 1.17 $ 932 The following is a summary of the status of the Company’s restricted stock as of March 31, 2017, and changes therein during the six month period then ended: Number of Restricted Weighted- average Grant Date Fair Value Nonvested at September 30, 2016 31,896 $ 13.11 Granted 23,971 16.28 Vested — — Forfeited — — Nonvested at March 31, 2017 55,867 $ 14.50

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurement	10. Fair Value Measurement The following disclosures show the hierarchal disclosure framework associated within the level of pricing observations utilized in measuring assets and liabilities at fair value. The definition of fair value maintains the exchange price notion in earlier definitions of fair value but focuses on the exit price of the asset or liability. The exit price is the price that would be received to sell the asset or paid to transfer the liability adjusted for certain inherent risks and restrictions. Expanded disclosures are also required about the use of fair value to measure assets and liabilities. The following table presents information about the Company’s securities, derivatives, other real estate owned, impaired loans and mortgage servicing rights measured at fair value as of March 31, 2017 and September 30, 2016 and indicates the fair value hierarchy of the valuation techniques utilized by the Bank to determine such fair value: Fair Value Measurement at March 31, 2017 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of December 31, 2016 Securities available-for-sale measured on a recurring basis Mortgage backed securities $ — $ 228,122 $ — $ 228,122 Obligations of states and political subdivisions — 69,335 — 69,335 U.S. government agencies — 23,463 — 23,463 Corporate obligations — 36,045 8,735 44,780 Other debt securities — 29,590 — 29,590 Equity securities-financial services 25 — — 25 Total debt and equity securities $ 25 $ 386,555 $ 8,735 $ 395,315 Derivatives $ — $ 1,397 $ — $ 1,397 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 3,315 $ 3,315 Impaired loans $ — $ — $ 19,830 $ 19,830 Mortgage servicing rights $ — $ — $ 321 $ 321 Fair Value Measurement at September 30, 2016 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of September 30, 2016 Securities available-for-sale measured on a recurring basis Mortgage backed securities $ — $ 219,162 $ — $ 219,162 Obligations of states and political subdivisions — 73,690 — 73,690 U.S. government agencies — 25,941 — 25,941 Corporate obligations — 31,433 6,985 38,418 Other debt securities — 32,674 500 33,174 Equity securities-financial services 25 — — 25 Total debt and equity securities $ 25 $ 382,900 $ 7,485 $ 390,410 Derivatives $ — $ 453 $ — $ 453 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 2,659 $ 2,659 Impaired loans $ — $ — $ 22,218 $ 22,218 Mortgage Servicing rights $ — $ — $ 398 $ 398 The following tables present a summary of changes in the fair value of the Company’s Level III investments for the three and six month periods ended March 31, 2017 and 2016 (in thousands). Fair Value Measurement Using Significant Unobservable Inputs (Level III) Three Months Ended March 31, 2017 March 31, 2016 Beginning balance $ 8,238 $ 7,136 Purchases, sales, issuances, settlements, net 756 — Total unrealized gain (loss): Included in earnings — — Included in other comprehensive income (259 ) (64 ) Transfers in and/or out of Level III — — $ 8,735 $ 7,072 Fair Value Measurement Using Significant Unobservable Inputs (Level III) Six Months Ended March 31, 2017 March 31, 2016 Beginning balance $ 7,485 $ 4,211 Purchases, sales, issuances, settlements, net 756 3,000 Total unrealized gain (loss): Included in earnings — — Included in other comprehensive income 494 (139 ) Transfers in and/or out of Level III — — $ 8,735 $ 7,072 Each financial asset and liability is identified as having been valued according to a specified level of input, 1, 2 or 3. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Fair values determined by Level 2 inputs utilize inputs other than quoted prices included in Level 1 that are observable for the asset, either directly or indirectly. Level 2 inputs include quoted prices for similar assets in active markets, and inputs other than quoted prices that are observable for the asset or liability. Level 3 inputs are unobservable inputs for the asset, and include situations where there is little, if any, market activity for the asset or liability. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy, within which the fair value measurement in its entirety falls, has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset. The measurement of fair value should be consistent with one of the following valuation techniques: market approach, income approach, and/or cost approach. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities (including a business). For example, valuation techniques consistent with the market approach often use market multiples derived from a set of comparables. Multiples might lie in ranges with a different multiple for each comparable. The selection of where within the range the appropriate multiple falls requires judgment, considering factors specific to the measurement (qualitative and quantitative). Valuation techniques consistent with the market approach include matrix pricing. Matrix pricing is a mathematical technique used principally to value debt securities without relying exclusively on quoted prices for the specific securities, but rather by relying on a security’s relationship to other benchmark quoted securities. Most of the securities classified as available for sale are reported at fair value utilizing Level 2 inputs. For these securities, the Company obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quoted market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Securities reported at fair value utilizing Level 1 inputs are limited to actively traded equity securities whose market price is readily available from the New York Stock Exchange or the NASDAQ exchange. A few securities are valued using Level 3 inputs, all of these are classified as available for sale and are reported at fair value using Level 3 inputs. Mortgage servicing rights are also valued by an independent pricing service. Foreclosed real estate is measured at fair value, less cost to sell at the date of foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value, less cost to sell. Income and expenses from operations and changes in valuation allowance are included in the net expenses from foreclosed real estate. Impaired loans are reported at fair value utilizing level three inputs. For these loans, a review of the collateral is conducted and an appropriate allowance for loan losses is allocated to the loan. At March 31, 2017, 177 impaired loans with a carrying value of $20.3 million were reduced by specific valuation allowance totaling $485,000 resulting in a net fair value of $19.8 million based on Level 3 inputs. At September 30, 2016, 205 impaired loans with a carrying value of $22.6 million were reduced by a specific valuation totaling $347,000 resulting in a net fair value of $22.2 million based on Level 3 inputs. The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which the Company has utilized Level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range March 31, 2017 Impaired loans $ 19,830 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 50% (23.4%) Foreclosed real estate owned 3,315 Appraisal of collateral (1) Appraisal adjustments (2) 20% to 50% (21.0%) Mortgage servicing rights 321 Discounted cash flow Discount rate 12% to 16% (12.5%) Prepayment speeds 9% to 35% (15.0%) Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range September 30, 2016: Impaired loans $ 22,218 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 60% (23.0%) Foreclosed real estate owned 2,659 Appraisal of collateral (1) Appraisal adjustments (2) 20% to 46% (22.1%) Mortgage servicing rights 398 Discounted cash flow Discount rate 12% to 16% (12.0%) Prepayment speeds 2% to 33% (17.2%) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range of liquidation expenses and other appraisal adjustments are presented as a percent of the appraisal. The fair values presented represent the Company’s best estimate of fair value using the methodologies discussed below. Disclosures about Fair Value of Financial Instruments The fair values presented represent the Company’s best estimate of fair value using the methodologies discussed below (in thousands). March 31, 2017 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 36,443 $ 36,443 $ — $ — $ 36,443 Certificates of deposit 1,000 — — 1,010 1,010 Investment and mortgage backed securities available for sale 395,315 25 386,555 8,735 395,315 Loans receivable, net 1,208,497 — — 1,203,706 1,203,706 Accrued interest receivable 5,929 5,929 — — 5,929 Regulatory stock 13,961 13,961 — — 13,961 Mortgage servicing rights 321 — — 321 321 Derivatives 1,397 — 1,397 — 1,397 Bank owned life insurance 37,112 37,112 — — 37,112 Financial liabilities: Deposits $ 1,238,375 $ 691,270 $ — $ 548,202 $ 1,239,472 Short-term borrowings 120,951 120,951 — — 120,951 Other borrowings 199,168 — — 199,219 199,219 Advances by borrowers for taxes and insurance 9,115 9,115 — — 9,115 Accrued interest payable 863 863 — — 863 September 30, 2016 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 43,658 $ 43,658 $ — $ — $ 43,658 Certificates of deposit 1,250 — — 1,269 1,269 Investment and mortgage backed securities available for sale 390,410 25 382,900 7,485 390,410 Loans receivable, net 1,219,213 — — 1,237,759 1,237,759 Accrued interest receivable 5,769 5,769 — — 5,769 Regulatory stock 15,463 15,463 — — 15,463 Mortgage servicing rights 398 — — 398 398 Derivatives 453 — 453 — 453 Bank owned life insurance 36,593 36,593 — — 36,593 Financial liabilities: Deposits $ 1,214,820 $ 702,151 $ — $ 516,743 $ 1,218,894 Short-term borrowings 129,460 129,460 — — 129,460 Other borrowings 230,601 — — 231,911 231,911 Advances by borrowers for taxes and insurance 4,956 4,956 — — 4,956 Accrued interest payable 1,046 1,046 — — 1,046 Financial instruments are defined as cash, evidence of an ownership interest in an entity, or a contract which creates an obligation or right to receive or deliver cash or another financial instrument from/to a second entity on potentially favorable or unfavorable terms. Fair value is defined as the amount at which a financial instrument could be exchanged in a current transaction between willing parties other than in a forced or liquidation sale. If a quoted market price is available for a financial instrument, the fair value would be calculated based upon the market price per trading unit of the instrument. If no readily available market exists, the fair value for financial instruments should be based upon management’s judgment regarding current economic conditions, interest rate risk, expected cash flows, future estimated losses, and other factors as determined through various option pricing formulas or simulation modeling. As many of these assumptions result from judgments made by management based upon estimates which are inherently uncertain, the resulting values may not be indicative of the amount realizable in the sale of a particular financial instrument. In addition, changes in the assumptions on which the values are based may have a significant impact on the resulting estimated values. As certain assets and liabilities, such as deferred tax assets, premises and equipment, and many other operational elements of the Bank, are not considered financial instruments but have value, this fair value of financial instruments would not represent the full market value of the Company. The Company employed simulation modeling in determining the fair value of financial instruments for which quoted market prices were not available based upon the following assumptions: Cash and Cash Equivalents, Accrued Interest Receivable, Short-Term Borrowings, Advances by Borrowers for Taxes and Insurance, and Accrued Interest Payable The fair value approximates the current book value. Bank-Owned Life Insurance The fair value is equal to the cash surrender value of the Bank-owned life insurance. Investment and Mortgage-Backed Securities Available for Sale and Regulatory Stock The fair value of investment and mortgage-backed securities available for sale is equal to the available quoted market price. If no quoted market price is available, fair value is estimated using the quoted market price for similar securities. Since the Regulatory stock is not actively traded on a secondary market and held exclusively by member financial institutions, the fair market value approximates the carrying amount. For certain securities which are not traded in active markets or are subject to transfer restrictions, valuations are adjusted to reflect illiquidity and/or non-transferability, and such adjustments are generally based on available market evidence (Level 3). In the absence of such evidence, management’s best estimate is used. Management’s best estimate consists of both internal and external support on certain Level 3 investments. Internal cash flow models using a present value formula that includes assumptions market participants would use along with indicative exit pricing obtained from broker/dealers (where available) are used to support fair values of certain Level 3 investments, if applicable. Loans Receivable The fair values of loans are estimated using discounted cash flow analyses, using market rates at the balance sheet date that reflect the credit and interest rate-risk inherent in the loans. Projected future cash flows are calculated based upon contractual maturity or call dates, projected repayments and prepayments of principal. Generally, for variable rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values. Mortgage Servicing Rights The Company utilizes a third party provider to estimate the fair value of certain loan servicing rights. Fair value for the purpose of this measurement is defined as the amount at which the asset could be exchanged in a current transaction between willing parties, other than in a forced liquidation. Derivatives Fair values of interest rate cap and interest rate swap contracts are based on dealer quotes. Deposits (including Certificates of Deposit) The fair values disclosed for demand, savings, and money market deposit accounts are valued at the amount payable on demand as of quarter-end. Fair values for time deposits are estimated using a discounted cash flow calculation that applies contractual costs currently being offered in the existing portfolio to current market rates being offered for deposits of similar remaining maturities. Other Borrowings Fair values for other borrowings are estimated using a discounted cash flow calculation that applies contractual costs currently being offered in the existing portfolio to current market rates being offered for other borrowings of similar remaining maturities. Commitments to Extend Credit These financial instruments are generally not subject to sale, and fair values are not readily available. The carrying value, represented by the net deferred fee arising from the unrecognized commitment, and the fair value, determined by discounting the remaining contractual fee over the term of the commitment using fees currently charged to enter into similar agreements with similar credit risk, are not considered material for disclosure.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Loss	11. Accumulated Other Comprehensive Loss The activity in accumulated other comprehensive loss for the three and six month periods ended March 31, 2017 and 2016 is as follows (in thousands): Accumulated Other Comprehensive Loss Defined Benefit Pension Plan Unrealized (Losses) on Securities Available for Sale Derivatives Total Balance at December 31, 2016 $ (5,993 ) $ (2,801 ) $ 899 $ (7,895 ) Other comprehensive income before reclassifications 4,714 781 25 5,520 Amounts reclassified from accumulated other comprehensive loss, net of tax 13 — (2 ) 11 Period change 4,727 781 23 5,531 Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) Balance at December 31, 2015 $ (5,246 ) $ 684 $ — $ (4,562 ) Other comprehensive income before reclassifications — 3,287 — 3,287 Amounts reclassified from accumulated other comprehensive loss, net of tax 79 (241 ) — (162 ) Period change 79 3,046 — 3,125 Balance at March 31, 2016 $ (5,167 ) $ 3,730 $ — $ (1,437 ) Accumulated Other Comprehensive Income/(Loss) Defined Benefit Pension Plan Unrealized Gains (Losses) on Securities Available for Sale Derivatives Total Balance at September 30, 2016 $ (6,083 ) $ 3,952 $ 299 $ (1,832 ) Other comprehensive income (loss) before reclassifications 4,714 (5,972 ) 619 (639 ) Amounts reclassified from accumulated other comprehensive loss, net of tax 103 — 4 107 Period change 4,817 (5,972 ) 623 (532 ) Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) Balance at September 30, 2015 $ (5,325 ) $ 2,930 $ — $ (2,395 ) Other comprehensive income before reclassifications — 1,043 — 1,043 Amounts reclassified from accumulated other comprehensive loss, net of tax 158 (243 ) — (85 ) Period change 158 800 — 958 Balance at March 31, 2016 $ (5,167 ) $ 3,730 $ — $ (1,437 ) The following tables present significant amounts reclassified out of each component of accumulated other comprehensive loss for the three and six month periods ended March 31, 2017 and 2016: Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss for the Three Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2017 2016 Securities available for sale: Securities gains reclassified into earnings $ — $ 365 Gain on sale of investments Related income tax expense — (124 ) Income taxes Net effect on accumulated other comprehensive loss for the period — 241 Defined benefit pension plan: Amortization of net loss (23 ) (119 ) Compensation and employee Related income tax expense 10 40 Income taxes Net effect on accumulated other comprehensive loss for the period (13 ) (79 ) Derivatives and hedging activities: Interest expense, effective portion 5 — Interest expense Related income tax expense (3 ) — Income taxes Net effect on accumulated other comprehesive loss for the period 2 (79 ) Total reclassification for the period $ (11 ) $ 162 Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss for the Six Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2017 2016 Securities available for sale: Securities gains reclassified into earnings $ — $ 368 Gain on sale of investments Related income tax expense — (125 ) Income taxes Net effect on accumulated other comprehensive loss for the period — 243 Defined benefit pension plan: Amortization of net loss (159 ) (239 ) Compensation and employee benefits Related income tax expense 56 81 Income taxes Net effect on accumulated other comprehensive loss for the period (103 ) (158 ) Derivative and hedging activities: Interest expense, effective portion (6 ) — Interest expense Related income tax expense 2 — Income taxes Net effect on accumulated other comprehensive loss for the period (4 ) — Total reclassification for the period $ (107 ) $ 85

Derivative and Hedging Activiti

Derivative and Hedging Activities	6 Months Ended
	Mar. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	12. Derivatives and Hedging Activities Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to certain variable rate borrowings. Fair Values of Derivative Instruments on the Consolidated Balance Sheet The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheet as of March 31, 2017 and September 30, 2016 (in thousands). Fair Values of Derivative Instruments Asset Derivatives As of March 31, 2017 As of September 30, 2016 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest Rate Products Other Assets $ 1,397 Other Assets $ 453 Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company has entered into interest rate swaps as part of its interest rate risk management strategy. These interest rate swaps are designated as cash flow hedges and involve the receipt of variable rate amounts from a counterparty in exchange for the Company making fixed payments. As of March 31, 2017, the Company had three interest rate swaps with a notional principal amount of $50 million associated with the Company’s cash outflows associated with various FHLB advances. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (outside of earnings), net of tax, and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. The Company assesses the effectiveness of each hedging relationship by comparing the changes in cash flows of the derivative hedging instrument with the changes in cash flows of the designated hedged transactions. The Company did not recognize any hedge ineffectiveness in earnings during the period ended March 31, 2017. Amounts reported in accumulated other comprehensive loss related to derivatives will be reclassified to interest income/expense as interest payments are made/received on the Company’s variable-rate assets/liabilities. During the three months ended March 31, 2017, the Company had $5,000 of reclassifications to interest income. During the six months ended March 31, 2017, the Company had $6,000 of reclassifications to interest expense. During the next twelve months, the Company estimates that $0 will be reclassified as a decrease in interest expense. The tables below present the pre-tax net gains (losses) of the Company’s cash flow hedges for the three and six month periods ended March 31, 2017 and 2016, respectively, and where they were recorded in the Consolidated Statement of Income, (in thousands). Derivatives in Cash Flow Hedging Relationships Gain Recognized in OCI on Derivative (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Gain Reclassified from Accumulated OCI into Income (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Three Months Ended March 31, 2017 2016 2017 2016 2017 2016 Interest Rate Products $ 40 $ — Interest expense $ 5 $ — Other non-interest income $ — $ — Ending balance of OCI Total $ 40 $ — $ 5 $ — $ — $ — Derivatives in Cash Flow Hedging Relationships Gain Recognized in OCI on Derivative (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Six Months Ended March 31, 2017 2016 2017 2016 2017 2016 Interest Rate Products $ 1,092 $ — Interest expense $ (6 ) $ — Other non-interest income $ — $ — Ending balance of OCI Total $ 1,092 $ — $ (6 ) $ — $ — $ — Credit-risk-related Contingent Features The Company has agreements with its derivative counterparties that contain a provision where if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. The Company also has agreements with certain of its derivative counterparties that contain a provision where if the Company fails to maintain its status as a well / adequately capitalized institution, then the counterparty could terminate the derivative positions and the Company would be required to settle its obligations under the agreements. As of March 31, 2017 the Company had no derivatives in a net liability position and was not required to post collateral against its obligations under these agreements. If the Company had breached any of these provisions at March 31, 2017, it could have been required to settle its obligations under the agreements at the termination value.

Recent Accounting Pronounceme21

Recent Accounting Pronouncements (Policies)	6 Months Ended
	Mar. 31, 2017
Accounting Changes And Error Corrections [Abstract]
Revenue from Contracts with Customers	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers Topic 606 In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606). Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Deferral of the Effective Date In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date
Financial Instruments	In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments
Lease	In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842)
Derivatives and Hedging	In March 2016, the FASB issued ASU 2016-05, Derivatives and Hedging (Topic 815) . Topic 815 For public business entities, the amendments in this Update are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. For all other entities, the amendments in this Update are effective for financial statements issued for fiscal years beginning after December 15, 2017, and interim periods within fiscal years beginning after December 15, 2018. An entity has an option to apply the amendments in this Update on either a prospective basis or a modified retrospective basis. Early adoption is permitted, including adoption in an interim period. This Update is not expected to have a significant impact on the Company’s financial statements. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815)
Investments	In March 2016, the FASB issued ASU 2016-07, Investments – Equity Method and Joint Ventures (Topic 323)
Statement of Cash Flows	In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments
Business Combinations	In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business
Goodwill Impairment	In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment To simplify the subsequent measurement of goodwill, the FASB eliminated Step 2 from the goodwill impairment test. In computing the implied fair value of goodwill under Step 2, an entity had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities (including unrecognized assets and liabilities) following the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. Instead, under the amendments in this Update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting units fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. A public business entity that is a U.S. Securities and Exchange Commission (“SEC”) filer should adopt the amendments in this Update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. A public business entity that is not an SEC filer should adopt the amendments in this Update for its annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2020. All other entities, including not-for-profit entities, that are adopting the amendments in this Update should do so for their annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2021. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations.
Other Income	In February 2017, the FASB issued ASU 2017-05, Other Income — Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) The amendments in this Update clarify what constitutes a financial asset within the scope of Subtopic 610-20. The amendments also clarify that entities should identify each distinct nonfinancial asset or in substance nonfinancial asset that is promised to a counterparty and to derecognize each asset when the counterparty obtains control. There is also additional guidance provided for partial sales of a nonfinancial asset and when derecognition, and the related gain or loss, should be recognized. The amendments in this Update are effective at the same time as the amendments in Update 2014-09. Therefore, for public entities, the amendments are effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. For all other entities, the amendments in this Update are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations.
Defined Benefit Pension Plans	In February 2017, the FASB issued ASU 2017-06 , Plan Accounting: Defined Benefit Pension Plans (Topic 960), Defined Contribution Pension Plans (Topic 962), and Health and Welfare Benefit Plans (Topic 965) This Update relates primarily to the reporting by an employee benefit plan for its interest in a master trust, which is a trust for which a regulated financial institution serves as a trustee or custodian and in which assets of more than one plan sponsored by a single employer or by a group of employers under common control are held. For each master trust in which a plan holds an interest, the amendments in this Update require a plan's interest in that master trust and any change in that interest to be presented in separate line items in the statement of net assets available for benefits and in the statement of changes in net assets available for benefits, respectively. The amendments in this Update remove the requirement to disclose the percentage interest in the master trust for plans with divided interests and require that all plans disclose the dollar amount of their interest in each of those general types of investments, which supplements the existing requirement to disclose the master trusts balances in each general type of investments. There are also increased disclosure requirements for investments in master trusts. The amendments in this Update are effective for fiscal years beginning after December 15, 2018. Early adoption is permitted. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations.
Compensation	In March 2017, the FASB issued ASU 2017-07, Compensation — Retirement Benefits (Topic 715) The amendments in this Update require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost as defined in paragraphs 715-30-35-4 and 715-60-35-9 are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. If a separate line item or items are used to present the other components of net benefit cost, that line item or items must be appropriately described. If a separate line item or items are not used, the line item or items used in the income statement to present the other components of net benefit cost must be disclosed. For public business entities, the amendments in this Update are effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. For all other entities, the amendments in the Update are effective for annual periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of an annual period for which financial statements (interim or annual) have not been issued or made available for issuance. The Company is currently evaluating the impact the adoption of the standard will have on the Company’s financial position or results of operations.
Receivables	In March 2017, the FASB issued ASU 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20).

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Composition of the Weighted-Average Common Shares (Denominator) Used in the Basic and Diluted Earnings Per Share Computation	The following table sets forth the composition of the weighted-average common shares (denominator) used in the basic and diluted earnings per share computation for the three and six month periods ended March 31, 2017 and 2016. Three Months Ended Six Months Ended March 31, March 31, March 31, March 31, 2017 2016 2017 2016 Weighted-average common shares outstanding 18,133,095 18,133,095 18,133,095 18,133,095 Average treasury stock shares (6,618,067 ) (6,793,799 ) (6,670,049 ) (6,793,553 ) Average unearned ESOP shares (888,285 ) (933,559 ) (894,004 ) (939,246 ) Average unearned non-vested shares (33,746 ) (20,584 ) (42,958 ) (24,681 ) Weighted average common shares and common stock equivalents used to calculate basic earnings per share 10,592,997 10,385,153 10,526,084 10,375,615 Additional common stock equivalents (non-vested stock) used to calculate diluted earnings per share 1,646 444 — — Additional common stock equivalents (stock options) used to calculate diluted earnings per share 97,317 139,100 91,157 140,155 Weighted average common shares and common stock equivalents used to calculate diluted earnings per share 10,691,960 10,524,697 10,617,241 10,515,770

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Mar. 31, 2017
Investments Debt And Equity Securities [Abstract]
Summary of Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Investment Securities Available for Sale	The amortized cost, gross unrealized gains and losses, and fair value of investment securities available for sale are summarized as follows (in thousands): March 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 120,437 $ 244 $ (1,591 ) $ 119,090 Freddie Mac 95,669 73 (1,136 ) 94,606 Governmental National Mortgage Association 14,610 34 (218 ) 14,426 Total mortgage-backed securities 230,716 351 (2,945 ) 228,122 Obligations of states and political subdivisions 68,995 1,314 (974 ) 69,335 U.S. government agency securities 23,344 119 — 23,463 Corporate obligations 45,315 203 (738 ) 44,780 Other debt securities 29,980 122 (512 ) 29,590 Total debt securities 398,350 2,109 (5,169 ) 395,290 Equity securities - financial services 25 — — 25 Total $ 398,375 $ 2,109 $ (5,169 ) $ 395,315 September 30, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 115,535 $ 1,891 $ (173 ) $ 117,253 Freddie Mac 84,486 1,369 (85 ) 85,770 Governmental National Mortgage Association 16,091 76 (28 ) 16,139 Total mortgage-backed securities 216,112 3,336 (286 ) 219,162 Obligations of states and political subdivisions 71,323 2,432 (65 ) 73,690 U.S. government agency securities 25,669 272 — 25,941 Corporate obligations 38,331 599 (512 ) 38,418 Other debt securities 32,962 428 (216 ) 33,174 Total debt securities 384,397 7,067 (1,079 ) 390,385 Equity securities - financial services 25 — — 25 Total $ 384,422 $ 7,067 $ (1,079 ) $ 390,410
Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	The amortized cost and fair value of debt securities at March 31, 2017, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties (in thousands): Available For Sale Amortized Cost Fair Value Due in one year or less $ 15,986 $ 16,013 Due after one year through five years 35,680 35,666 Due after five years through ten years 92,538 92,271 Due after ten years 254,146 251,340 Total $ 398,350 $ 395,290
Schedule of Gross Unrealized Losses and Fair Value	The following table shows the Company’s gross unrealized losses and fair value, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position (dollars in thousands): March 31, 2017 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 61 $ 76,418 $ (1,192 ) $ 11,033 $ (399 ) $ 87,451 $ (1,591 ) Freddie Mac 50 66,922 (909 ) 6,701 (227 ) 73,623 (1,136 ) Governmental National Mortgage Association 9 7,292 (181 ) 2,373 (37 ) 9,665 (218 ) Obligations of states and political subdivisions 29 34,982 (974 ) — — 34,982 (974 ) Corporate obligations 23 18,850 (437 ) 6,198 (301 ) 25,048 (738 ) Other debt securities 18 12,303 (338 ) 8,804 (174 ) 21,107 (512 ) Total 190 $ 216,767 $ (4,031 ) $ 35,109 $ (1,138 ) $ 251,876 $ (5,169 ) September 30, 2016 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 17 $ 6,841 $ (21 ) $ 12,261 $ (152 ) $ 19,102 $ (173 ) Freddie Mac 11 7,457 (11 ) 6,375 (74 ) 13,832 (85 ) Governmental National Mortgage Association 5 4,704 (16 ) 1,267 (12 ) 5,971 (28 ) Obligations of states and political subdivisions 12 14,420 (65 ) — — 14,420 (65 ) Corporate obligations 12 8,778 (172 ) 5,303 (340 ) 14,081 (512 ) Other debt securities 13 6,582 (126 ) 6,914 (90 ) 13,496 (216 ) Total 70 $ 48,782 $ (411 ) $ 32,120 $ (668 ) $ 80,902 $ (1,079 )

Loans Receivable, Net and All24

Loans Receivable, Net and Allowance for Loan Losses (Tables)	6 Months Ended
	Mar. 31, 2017
Summary of Loans Receivable	Loans receivable consist of the following (in thousands): March 31, 2017 September 30, 2016 Real estate loans: Residential $ 592,169 $ 596,645 Construction 3,928 1,733 Commercial 290,411 288,447 Commercial 34,125 39,978 Obligations of states and political subdivisions 61,746 56,923 Home equity loans and lines of credit 45,651 48,163 Auto Loans 186,697 193,078 Other 3,136 3,302 1,217,863 1,228,269 Less allowance for loan losses 9,366 9,056 Net loans $ 1,208,497 $ 1,219,213
Schedule of Investment and Unpaid Principal Balances for Impaired Loans	The following tables include the recorded investment and unpaid principal balances for impaired loans with the associated allowance amount at the dates indicated, if applicable (in thousands): Recorded Investment Unpaid Principal Balance Associated Allowance March 31, 2017 With no specific allowance recorded: Real estate loans Residential $ 5,351 $ 7,155 $ — Construction — — — Commercial 10,422 11,569 — Commercial 1,557 1,627 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 211 287 — Auto loans 208 290 — Other 24 29 — Total 17,773 20,957 — With an allowance recorded: Real estate loans Residential 1,660 1,990 128 Construction — — — Commercial 120 128 26 Commercial 185 199 125 Obligations of states and political subdivisions — — — Home equity loans and lines of credit 5 5 5 Auto loans 572 575 201 Other — — — Total 2,542 2,897 485 Total: Real estate loans Residential 7,011 9,145 128 Construction — — — Commercial 10,542 11,697 26 Commercial 1,742 1,826 125 Obligations of states and political subdivisions — — — Home equity loans and lines of credit 216 292 5 Auto loans 780 865 201 Other 24 29 — Total Impaired Loans $ 20,315 $ 23,854 $ 485 Recorded Investment Unpaid Principal Balance Associated Allowance September 30, 2016 With no specific allowance recorded: Real Estate Loans Residential $ 6,721 $ 9,016 $ — Construction — — — Commercial 10,939 12,928 — Commercial 1,698 1,725 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 361 432 — Auto Loans 253 365 — Other 22 22 — Total 19,994 24,488 — With an allowance recorded: Real Estate Loans Residential 2,000 2,151 198 Construction — — — Commercial 298 303 36 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto Loans 273 273 113 Other — — — Total 2,571 2,727 347 Total: Real Estate Loans Residential 8,721 11,167 198 Construction — — — Commercial 11,237 13,231 36 Commercial 1,698 1,725 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 361 432 — Auto Loans 526 638 113 Other 22 22 — Total Impaired Loans $ 22,565 $ 27,215 $ 347 The following tables represent the average recorded investments in the impaired loans and the related amount of interest recognized during the time within the period that the impaired loans were impaired (in thousands): For the Three Months Ended March 31, 2017 2016 2017 2016 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 5,573 $ 7,296 $ 9 $ 22 Construction — — — — Commercial 9,218 12,128 67 131 Commercial 1,637 1,919 29 37 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 202 594 — — Auto loans 102 228 — — Other 8 — — — Total 16,740 22,165 105 190 With an allowance recorded: Real estate loans Residential 1,985 2,679 — 4 Construction — — — — Commercial 341 1,490 — — Commercial 100 6 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 5 59 — — Auto loans 291 222 2 2 Other — 1 — — Total 2,722 4,457 2 6 Total: Real estate loans Residential 7,558 9,975 9 26 Construction — — — — Commercial 9,559 13,618 67 131 Commercial 1,737 1,925 29 37 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 207 653 — — Auto loans 393 450 2 2 Other 8 1 — — Total Impaired Loans $ 19,462 $ 26,622 $ 107 $ 196 For the Six Months Ended March 31, 2017 2016 2017 2016 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 6,049 $ 8,040 $ 21 $ 48 Construction — — — — Commercial 9,890 12,908 172 307 Commercial 1,665 1,350 62 52 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 260 672 — 2 Auto loans 119 255 — 2 Other 8 — — — Total 17,991 23,225 255 411 With an allowance recorded: Real estate loans Residential 2,025 2,636 — 9 Construction — — — — Commercial 345 974 — — Commercial 59 4 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 4 66 — — Auto loans 253 181 6 3 Other — — — — Total 2,686 3,861 6 12 Total: Real estate loans Residential 8,074 10,676 21 57 Construction — — — — Commercial 10,235 13,882 172 307 Commercial 1,724 1,354 62 52 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 264 738 — 2 Auto loans 372 436 6 5 Other 8 — — — Total Impaired Loans $ 20,677 $ 27,086 $ 261 $ 423
Changes in Accretable Yield for Purchased Credit-Impaired Loans	Changes in the accretable yield for purchased credit-impaired loans were as follows, since acquisition, for the three and six month periods ended March 31, 2017 and March 31, 2016 (in thousands): Three Months Ended March 31, 2017 2016 Balance at beginning of period $ 453 $ 448 Reclassification, new additions and other 82 — Accretion (75 ) (83 ) Balance at end of period $ 460 $ 365 Six Months Ended March 31, 2017 2016 Balance at beginning of period $ 478 $ 258 Reclassification, new additions and other 118 240 Accretion (136 ) (133 ) Balance at end of period $ 460 $ 365
Summary of Additional Information Regarding Loans Acquired and Accounted	The following table presents additional information regarding loans acquired and accounted for in accordance with ASC 310-30 (in thousands): March 31, 2017 September 30, 2016 Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Outstanding balance $ 6,309 $ 6,893 Carrying amount $ 5,098 $ 5,563
Schedule of Loans Evaluated for Impairment	The following tables show the amount of loans in each category that was individually and collectively evaluated for impairment at the dates indicated (in thousands): Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment March 31, 2017 Real estate loans: Residential $ 592,169 $ 7,011 $ — $ 585,158 Construction 3,928 — — 3,928 Commercial 290,411 10,542 4,453 275,416 Commercial 34,125 1,742 321 32,062 Obligations of states and political subdivisions 61,746 — — 61,746 Home equity loans and lines of credit 45,651 216 324 45,111 Auto loans 186,697 780 — 185,917 Other 3,136 24 — 3,112 Total $ 1,217,863 $ 20,315 $ 5,098 $ 1,192,450 Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment September 30, 2016 Real estate loans: Residential $ 596,645 $ 8,721 $ — $ 587,924 Construction 1,733 — — 1,733 Commercial 288,447 11,237 4,615 272,595 Commercial 39,978 1,698 411 37,869 Obligations of states and political sub divisions 56,923 — — 56,923 Home equity loans and lines of credit 48,163 361 537 47,265 Auto loans 193,078 526 — 192,552 Other 3,302 22 — 3,280 Total $ 1,228,269 $ 22,565 $ 5,563 $ 1,200,141
Classes of the Loan Portfolio, Internal Risk Rating System	The following tables present the classes of the loan portfolio summarized by the aggregate Pass and the criticized categories of Special Mention, Substandard, and Doubtful or Loss within the internal risk rating system at March 31, 2017 and September 30, 2016 (in thousands): Pass Special Mention Substandard Doubtful or Loss Total March 31, 2017 Commercial real estate loans $ 266,868 $ 5,225 $ 18,318 $ — $ 290,411 Commercial 30,657 177 3,291 — 34,125 Obligations of states and political subdivisions 61,746 — — — 61,746 Total $ 359,271 $ 5,402 $ 21,609 $ — $ 386,282 Pass Special Mention Substandard Doubtful or Loss Total September 30, 2016 Commercial real estate loans $ 260,088 $ 8,886 $ 19,473 $ — $ 288,447 Commercial 36,684 180 3,114 — 39,978 Obligations of states and political subdivisions 56,923 — — — 56,923 Total $ 353,695 $ 9,066 $ 22,587 $ — $ 385,348
Schedule of Performing or non-performing Loans	The following tables present the risk ratings in the consumer categories of performing and non-performing loans at March 31, 2017 and September 30, 2016 (in thousands): Performing Non- performing Purchased Credit Impaired Total March 31, 2017 Real estate loans: Residential $ 584,544 $ 7,625 $ — $ 592,169 Construction 3,928 — — 3,928 Home equity loans and lines of credit 45,053 274 324 45,651 Auto loans 185,907 790 — 186,697 Other 3,102 34 — 3,136 Total $ 822,534 $ 8,723 $ 324 $ 831,581 Performing Non- performing Purchased Impaired Credit Total September 30, 2016 Real estate loans: Residential $ 587,673 $ 8,972 $ — $ 596,645 Construction 1,733 — — 1,733 Home equity loans and lines of credit 47,213 413 537 48,163 Auto loans 192,734 344 — 193,078 Other 3,271 31 — 3,302 Total $ 832,624 $ 9,760 $ 537 $ 842,921
Classes of the Loan Portfolio Summarized by the Aging Categories	The following tables present the classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans as of March 31, 2017 and September 30, 2016 (in thousands): Current 31-60 Days Past Due 61-90 Days Past Due Greater than 90 Days Past Due and still accruing Non-Accrual Total Past Due and Non- Accrual Purchased Credit Impaired Total Loans March 31, 2017 Real estate loans Residential $ 582,864 $ 1,081 $ 599 $ — $ 7,625 $ 9,305 $ — $ 592,169 Construction 3,928 — — — — — — 3,928 Commercial 282,390 284 — — 3,284 3,568 4,453 290,411 Commercial 32,994 80 — — 730 810 321 34,125 Obligations of states and political subdivisions 61,746 — — — — — — 61,746 Home equity loans and lines of credit 45,027 18 8 — 274 300 324 45,651 Auto loans 185,398 427 82 — 790 1,299 — 186,697 Other 3,054 48 — — 34 82 — 3,136 Total $ 1,197,401 $ 1,938 $ 689 $ — $ 12,737 $ 15,364 $ 5,098 $ 1,217,863 Current 31-60 Days Past Due 61-90 Days Past Due Greater than 90 Days Past Due and still accruing Non-Accrual Total Past Due and Non- Accrual Purchased Credit Impaired Total Loans September 30, 2016 Real estate loans Residential $ 585,517 $ 1,496 $ 660 $ — $ 8,972 $ 11,128 $ — $ 596,645 Construction 1,733 — — — — — — 1,733 Commercial 279,019 1,093 191 — 3,529 4,813 4,615 288,447 Commercial 38,862 185 57 — 463 705 411 39,978 Obligations of states and political subdivisions 56,923 — — — — — — 56,923 Home equity loans and lines of credit 47,026 40 147 — 413 600 537 48,163 Auto loans 191,785 717 232 — 344 1,293 — 193,078 Other 3,264 7 — — 31 38 — 3,302 Total $ 1,204,129 $ 3,538 $ 1,287 $ — $ 13,752 $ 18,577 $ 5,563 $ 1,228,269
Summary of Primary Segments of ALL	The following tables summarize changes in the primary segments of the ALL for the three and six month periods ending March 31, 2017 and 2016 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total ALL balance at December 31, 2016 $ 4,450 $ 23 $ 795 $ 965 $ 234 $ 441 $ 2,062 $ 25 $ 347 $ 9,342 Charge-offs (290 ) — (128 ) (1 ) — (6 ) (544 ) — — (969 ) Recoveries 5 — — — — 2 232 4 — 243 Provision (35 ) 7 371 (13 ) 10 8 158 (5 ) 249 750 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 ALL balance at December 31, 2015 $ 4,747 $ 14 $ 858 $ 705 $ 187 $ 389 $ 1,754 $ 27 $ 576 $ 9,257 Charge-offs (308 ) — (9 ) — — (29 ) (234 ) — — (580 ) Recoveries — — 52 — — 3 80 3 — 138 Provision 216 10 67 33 9 26 325 (5 ) (81 ) 600 ALL balance at March 31, 2016 $ 4,655 $ 24 $ 968 $ 738 $ 196 $ 389 $ 1,925 $ 25 $ 495 $ 9,415 ALL balance at September 30, 2016 $ 4,426 $ 13 $ 852 $ 882 $ 215 $ 455 $ 1,880 $ 25 $ 308 $ 9,056 Charge-offs (366 ) — (218 ) (20 ) — (6 ) (1,061 ) (4 ) — (1,675 ) Recoveries 6 — 10 — — 3 460 6 — 485 Provision 64 17 394 89 29 (7 ) 629 (3 ) 288 1,500 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 ALL balance at September 30, 2015 $ 5,140 $ 7 $ 671 $ 693 $ 189 $ 461 $ 1,570 $ 27 $ 161 $ 8,919 Charge-offs (399 ) — (9 ) (3 ) — (54 ) (422 ) — — (887 ) Recoveries 3 — 52 1 — 4 117 6 — 183 Provision (89 ) 17 254 47 7 (22 ) 660 (8 ) 334 1,200 ALL balance at March 31, 2016 $ 4,655 $ 24 $ 968 $ 738 $ 196 $ 389 $ 1,925 $ 25 $ 495 $ 9,415 Acquired loans are recorded at fair value on their purchase date without a carryover of the related allowance for loan losses. The following table summarizes the primary segments of the ALL, segregated into two categories, the amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment as of March 31, 2017 and September 30, 2016 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total Individually evaluated for impairment $ 128 $ — $ 26 $ 125 $ — $ 5 $ 201 $ — $ — $ 485 Collectively evaluated for impairment 4,002 30 1,012 826 244 440 1,707 24 596 8,881 ALL Balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 Individually evaluated for impairment $ 198 $ — $ 36 $ — $ — $ — $ 113 $ — $ — $ 347 Collectively evaluated for impairment 4,228 13 816 882 215 455 1,767 25 308 8,709 ALL balance at September 30, 2016 $ 4,426 $ 13 $ 852 $ 882 $ 215 $ 455 $ 1,880 $ 25 $ 308 $ 9,056
Summary of Troubled Debt Restructuring Granted	The following is a summary of troubled debt restructuring granted during the three months ended March 31, 2017 and 2016 (dollars in thousands): For the Three Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 1 $ 135 $ 135 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 3 $ 291 $ 291 For the Three Months Ended March 31, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 3 $ 587 $ 587 Construction — — — Commercial 1 77 77 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other — — — Total 4 $ 664 $ 664 The following is a summary of troubled debt restructuring granted during the six months ended March 31, 2017 and 2016 (dollars in thousands): For the Six Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 3 $ 379 $ 379 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 5 $ 535 $ 535 For the Six Months Ended March 31, 2016 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 4 $ 668 $ 668 Construction — — — Commercial 1 77 77 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other — — — Total 5 $ 745 $ 745
Eagle National Bancorp, Inc [Member]
Schedule of Investment and Unpaid Principal Balances for Impaired Loans	The carrying value of the loans acquired and accounted for in accordance with ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality Unpaid principal balance $ 3,468 Interest 717 Contractual cash flows 4,185 Non-accretable discount (1,973 ) Expected cash flows 2,212 Accretable discount (240 ) Estimated fair value $ 1,972

Deposits (Tables)

Deposits (Tables)	6 Months Ended
	Mar. 31, 2017
Banking And Thrift [Abstract]
Schedule of Deposits by Major Classifications	Deposits consist of the following major classifications (in thousands): March 31, 2017 September 30, 2016 Non-interest bearing demand accounts $ 150,762 $ 142,924 Interest bearing demand accounts 139,528 167,259 Money market accounts 255,502 249,947 Savings and club accounts 145,478 142,021 Certificates of deposit 547,105 512,669 Total $ 1,238,375 $ 1,214,820

Net Periodic Benefit Cost-Def26

Net Periodic Benefit Cost-Defined Benefit Plan (Tables)	6 Months Ended
	Mar. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Summary of the Components of Net Periodic Benefit Cost	The following table comprises the components of net periodic benefit cost for the three and six month periods ended March 31, 2017 and 2016 (in thousands): For the Three Months Ended March 31, For the Six Months Ended March 31, 2017 2016 2017 2016 Service Cost $ 69 $ 249 $ 378 $ 498 Interest Cost 208 245 443 490 Expected return on plan assets (348 ) (311 ) (689 ) (622 ) Amortization of unrecognized loss 23 119 159 239 Net periodic benefit cost $ (48 ) $ 302 $ 291 $ 605

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	6 Months Ended
	Mar. 31, 2017
Postemployment Benefits [Abstract]
Schedule of Stock Option Activity	The following is a summary of the Company’s stock option activity and related information for its option grants for the six month period ended March 31, 2017. Number of Stock Options Weighted- average Exercise Price Weighted- average Remaining Contractual Term (in Aggregate Intrinsic Value (in thousands) Outstanding, September 30, 2016 905,987 $ 12.35 1.67 $ 1,341 Granted — — — — Exercised 488,491 12.35 1.17 — Forfeited — — — — Outstanding, March 31, 2017 417,496 $ 12.35 1.17 $ 932 Exercisable at March 31, 2017 417,496 $ 12.35 1.17 $ 932
Schedule of Restricted Stock Option Activity	The following is a summary of the status of the Company’s restricted stock as of March 31, 2017, and changes therein during the six month period then ended: Number of Restricted Weighted- average Grant Date Fair Value Nonvested at September 30, 2016 31,896 $ 13.11 Granted 23,971 16.28 Vested — — Forfeited — — Nonvested at March 31, 2017 55,867 $ 14.50

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Securities, Derivatives, Other Real Estate Owned and Impaired Loans Measured at Fair Value	The following table presents information about the Company’s securities, derivatives, other real estate owned, impaired loans and mortgage servicing rights measured at fair value as of March 31, 2017 and September 30, 2016 and indicates the fair value hierarchy of the valuation techniques utilized by the Bank to determine such fair value: Fair Value Measurement at March 31, 2017 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of December 31, 2016 Securities available-for-sale measured on a recurring basis Mortgage backed securities $ — $ 228,122 $ — $ 228,122 Obligations of states and political subdivisions — 69,335 — 69,335 U.S. government agencies — 23,463 — 23,463 Corporate obligations — 36,045 8,735 44,780 Other debt securities — 29,590 — 29,590 Equity securities-financial services 25 — — 25 Total debt and equity securities $ 25 $ 386,555 $ 8,735 $ 395,315 Derivatives $ — $ 1,397 $ — $ 1,397 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 3,315 $ 3,315 Impaired loans $ — $ — $ 19,830 $ 19,830 Mortgage servicing rights $ — $ — $ 321 $ 321 Fair Value Measurement at September 30, 2016 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of September 30, 2016 Securities available-for-sale measured on a recurring basis Mortgage backed securities $ — $ 219,162 $ — $ 219,162 Obligations of states and political subdivisions — 73,690 — 73,690 U.S. government agencies — 25,941 — 25,941 Corporate obligations — 31,433 6,985 38,418 Other debt securities — 32,674 500 33,174 Equity securities-financial services 25 — — 25 Total debt and equity securities $ 25 $ 382,900 $ 7,485 $ 390,410 Derivatives $ — $ 453 $ — $ 453 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 2,659 $ 2,659 Impaired loans $ — $ — $ 22,218 $ 22,218 Mortgage Servicing rights $ — $ — $ 398 $ 398
Schedule of Changes in Fair Value of Level III Investments	The following tables present a summary of changes in the fair value of the Company’s Level III investments for the three and six month periods ended March 31, 2017 and 2016 (in thousands). Fair Value Measurement Using Significant Unobservable Inputs (Level III) Three Months Ended March 31, 2017 March 31, 2016 Beginning balance $ 8,238 $ 7,136 Purchases, sales, issuances, settlements, net 756 — Total unrealized gain (loss): Included in earnings — — Included in other comprehensive income (259 ) (64 ) Transfers in and/or out of Level III — — $ 8,735 $ 7,072 Fair Value Measurement Using Significant Unobservable Inputs (Level III) Six Months Ended March 31, 2017 March 31, 2016 Beginning balance $ 7,485 $ 4,211 Purchases, sales, issuances, settlements, net 756 3,000 Total unrealized gain (loss): Included in earnings — — Included in other comprehensive income 494 (139 ) Transfers in and/or out of Level III — — $ 8,735 $ 7,072
Summary of Additional Quantitative Information about Assets Measured at Fair Value on a Nonrecurring Basis	The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which the Company has utilized Level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range March 31, 2017 Impaired loans $ 19,830 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 50% (23.4%) Foreclosed real estate owned 3,315 Appraisal of collateral (1) Appraisal adjustments (2) 20% to 50% (21.0%) Mortgage servicing rights 321 Discounted cash flow Discount rate 12% to 16% (12.5%) Prepayment speeds 9% to 35% (15.0%) Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range September 30, 2016: Impaired loans $ 22,218 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 60% (23.0%) Foreclosed real estate owned 2,659 Appraisal of collateral (1) Appraisal adjustments (2) 20% to 46% (22.1%) Mortgage servicing rights 398 Discounted cash flow Discount rate 12% to 16% (12.0%) Prepayment speeds 2% to 33% (17.2%) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range of liquidation expenses and other appraisal adjustments are presented as a percent of the appraisal.
Schedule of Estimate of Fair Value Using Methodologies	The fair values presented represent the Company’s best estimate of fair value using the methodologies discussed below (in thousands). March 31, 2017 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 36,443 $ 36,443 $ — $ — $ 36,443 Certificates of deposit 1,000 — — 1,010 1,010 Investment and mortgage backed securities available for sale 395,315 25 386,555 8,735 395,315 Loans receivable, net 1,208,497 — — 1,203,706 1,203,706 Accrued interest receivable 5,929 5,929 — — 5,929 Regulatory stock 13,961 13,961 — — 13,961 Mortgage servicing rights 321 — — 321 321 Derivatives 1,397 — 1,397 — 1,397 Bank owned life insurance 37,112 37,112 — — 37,112 Financial liabilities: Deposits $ 1,238,375 $ 691,270 $ — $ 548,202 $ 1,239,472 Short-term borrowings 120,951 120,951 — — 120,951 Other borrowings 199,168 — — 199,219 199,219 Advances by borrowers for taxes and insurance 9,115 9,115 — — 9,115 Accrued interest payable 863 863 — — 863 September 30, 2016 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 43,658 $ 43,658 $ — $ — $ 43,658 Certificates of deposit 1,250 — — 1,269 1,269 Investment and mortgage backed securities available for sale 390,410 25 382,900 7,485 390,410 Loans receivable, net 1,219,213 — — 1,237,759 1,237,759 Accrued interest receivable 5,769 5,769 — — 5,769 Regulatory stock 15,463 15,463 — — 15,463 Mortgage servicing rights 398 — — 398 398 Derivatives 453 — 453 — 453 Bank owned life insurance 36,593 36,593 — — 36,593 Financial liabilities: Deposits $ 1,214,820 $ 702,151 $ — $ 516,743 $ 1,218,894 Short-term borrowings 129,460 129,460 — — 129,460 Other borrowings 230,601 — — 231,911 231,911 Advances by borrowers for taxes and insurance 4,956 4,956 — — 4,956 Accrued interest payable 1,046 1,046 — — 1,046

Accumulated Other Comprehensi29

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Summary of Activity in Accumulated Other Comprehensive Income (Loss)	The activity in accumulated other comprehensive loss for the three and six month periods ended March 31, 2017 and 2016 is as follows (in thousands): Accumulated Other Comprehensive Loss Defined Benefit Pension Plan Unrealized (Losses) on Securities Available for Sale Derivatives Total Balance at December 31, 2016 $ (5,993 ) $ (2,801 ) $ 899 $ (7,895 ) Other comprehensive income before reclassifications 4,714 781 25 5,520 Amounts reclassified from accumulated other comprehensive loss, net of tax 13 — (2 ) 11 Period change 4,727 781 23 5,531 Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) Balance at December 31, 2015 $ (5,246 ) $ 684 $ — $ (4,562 ) Other comprehensive income before reclassifications — 3,287 — 3,287 Amounts reclassified from accumulated other comprehensive loss, net of tax 79 (241 ) — (162 ) Period change 79 3,046 — 3,125 Balance at March 31, 2016 $ (5,167 ) $ 3,730 $ — $ (1,437 ) Accumulated Other Comprehensive Income/(Loss) Defined Benefit Pension Plan Unrealized Gains (Losses) on Securities Available for Sale Derivatives Total Balance at September 30, 2016 $ (6,083 ) $ 3,952 $ 299 $ (1,832 ) Other comprehensive income (loss) before reclassifications 4,714 (5,972 ) 619 (639 ) Amounts reclassified from accumulated other comprehensive loss, net of tax 103 — 4 107 Period change 4,817 (5,972 ) 623 (532 ) Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) Balance at September 30, 2015 $ (5,325 ) $ 2,930 $ — $ (2,395 ) Other comprehensive income before reclassifications — 1,043 — 1,043 Amounts reclassified from accumulated other comprehensive loss, net of tax 158 (243 ) — (85 ) Period change 158 800 — 958 Balance at March 31, 2016 $ (5,167 ) $ 3,730 $ — $ (1,437 )
Summary of Reclassification Out of Accumulated Other Comprehensive Income (Loss)	The following tables present significant amounts reclassified out of each component of accumulated other comprehensive loss for the three and six month periods ended March 31, 2017 and 2016: Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss for the Three Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2017 2016 Securities available for sale: Securities gains reclassified into earnings $ — $ 365 Gain on sale of investments Related income tax expense — (124 ) Income taxes Net effect on accumulated other comprehensive loss for the period — 241 Defined benefit pension plan: Amortization of net loss (23 ) (119 ) Compensation and employee Related income tax expense 10 40 Income taxes Net effect on accumulated other comprehensive loss for the period (13 ) (79 ) Derivatives and hedging activities: Interest expense, effective portion 5 — Interest expense Related income tax expense (3 ) — Income taxes Net effect on accumulated other comprehesive loss for the period 2 (79 ) Total reclassification for the period $ (11 ) $ 162 Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss for the Six Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2017 2016 Securities available for sale: Securities gains reclassified into earnings $ — $ 368 Gain on sale of investments Related income tax expense — (125 ) Income taxes Net effect on accumulated other comprehensive loss for the period — 243 Defined benefit pension plan: Amortization of net loss (159 ) (239 ) Compensation and employee benefits Related income tax expense 56 81 Income taxes Net effect on accumulated other comprehensive loss for the period (103 ) (158 ) Derivative and hedging activities: Interest expense, effective portion (6 ) — Interest expense Related income tax expense 2 — Income taxes Net effect on accumulated other comprehensive loss for the period (4 ) — Total reclassification for the period $ (107 ) $ 85

Derivatives and Hedging Activit

Derivatives and Hedging Activities (Tables)	6 Months Ended
	Mar. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Schedule of Fair Value of Derivative Financial Instruments as well as their Classification on Consolidated Balance Sheet	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheet as of March 31, 2017 and September 30, 2016 (in thousands). Fair Values of Derivative Instruments Asset Derivatives As of March 31, 2017 As of September 30, 2016 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest Rate Products Other Assets $ 1,397 Other Assets $ 453
Schedule of Pre-Tax Net Gains (Losses) of Cash flow Hedges	The tables below present the pre-tax net gains (losses) of the Company’s cash flow hedges for the three and six month periods ended March 31, 2017 and 2016, respectively, and where they were recorded in the Consolidated Statement of Income, (in thousands). Derivatives in Cash Flow Hedging Relationships Gain Recognized in OCI on Derivative (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Gain Reclassified from Accumulated OCI into Income (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Three Months Ended March 31, 2017 2016 2017 2016 2017 2016 Interest Rate Products $ 40 $ — Interest expense $ 5 $ — Other non-interest income $ — $ — Ending balance of OCI Total $ 40 $ — $ 5 $ — $ — $ — Derivatives in Cash Flow Hedging Relationships Gain Recognized in OCI on Derivative (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Six Months Ended March 31, 2017 2016 2017 2016 2017 2016 Interest Rate Products $ 1,092 $ — Interest expense $ (6 ) $ — Other non-interest income $ — $ — Ending balance of OCI Total $ 1,092 $ — $ (6 ) $ — $ — $ —

Nature of Operations and Basi31

Nature of Operations and Basis of Presentation - Additional Information (Detail)	Mar. 31, 2017
ESSA Bank & Trust [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage ownership of wholly owned subsidiary	100.00%

Earnings Per Share - Compositio

Earnings Per Share - Composition of the Weighted-Average Common Shares (Denominator) Used in the Basic and Diluted Earnings per Share Computation (Detail) - shares	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Weighted-average common shares outstanding	18,133,095	18,133,095	18,133,095	18,133,095
Average treasury stock shares	(6,618,067)	(6,793,799)	(6,670,049)	(6,793,553)
Average unearned ESOP shares	(888,285)	(933,559)	(894,004)	(939,246)
Average unearned non-vested shares	(33,746)	(20,584)	(42,958)	(24,681)
Weighted average common shares and common stock equivalents used to calculate basic earnings per share	10,592,997	10,385,153	10,526,084	10,375,615
Additional common stock equivalents (non-vested stock) used to calculate diluted earnings per share	1,646	444
Additional common stock equivalents (stock options) used to calculate diluted earnings per share	97,317	139,100	91,157	140,155
Weighted average common shares and common stock equivalents used to calculate diluted earnings per share	10,691,960	10,524,697	10,617,241	10,515,770

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - Stock Option [Member] - $ / shares	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	53,371	48,498
Average weighted price per share of anti-dilutive shares	$ 11.77	$ 12.90

Recent Accounting Pronounceme34

Recent Accounting Pronouncements - Additional Information (Detail) - ASU 2016-02, Leases [Member] - Maximum [Member]	6 Months Ended
	Mar. 31, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Estimated percentage increase in assets from recognition of leases	1.00%
Estimated percentage increase in liabilities from recognition of leases	1.00%

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Investment Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	$ 398,375		$ 384,422
Available for sale, Gross Unrealized Gains	2,109		7,067
Available for sale, Gross Unrealized Losses	(5,169)		(1,079)
Available for sale, Fair Value	395,315	$ 395,315	390,410
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	120,437		115,535
Available for sale, Gross Unrealized Gains	244		1,891
Available for sale, Gross Unrealized Losses	(1,591)		(173)
Available for sale, Fair Value	119,090		117,253
Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	95,669		84,486
Available for sale, Gross Unrealized Gains	73		1,369
Available for sale, Gross Unrealized Losses	(1,136)		(85)
Available for sale, Fair Value	94,606		85,770
Governmental National Mortgage Association [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	14,610		16,091
Available for sale, Gross Unrealized Gains	34		76
Available for sale, Gross Unrealized Losses	(218)		(28)
Available for sale, Fair Value	14,426		16,139
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	230,716		216,112
Available for sale, Gross Unrealized Gains	351		3,336
Available for sale, Gross Unrealized Losses	(2,945)		(286)
Available for sale, Fair Value	228,122		219,162
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	68,995		71,323
Available for sale, Gross Unrealized Gains	1,314		2,432
Available for sale, Gross Unrealized Losses	(974)		(65)
Available for sale, Fair Value	69,335		73,690
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	23,344		25,669
Available for sale, Gross Unrealized Gains	119		272
Available for sale, Fair Value	23,463		25,941
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	45,315		38,331
Available for sale, Gross Unrealized Gains	203		599
Available for sale, Gross Unrealized Losses	(738)		(512)
Available for sale, Fair Value	44,780		38,418
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	29,980		32,962
Available for sale, Gross Unrealized Gains	122		428
Available for sale, Gross Unrealized Losses	(512)		(216)
Available for sale, Fair Value	29,590		33,174
Total Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	398,350		384,397
Available for sale, Gross Unrealized Gains	2,109		7,067
Available for sale, Gross Unrealized Losses	(5,169)		(1,079)
Available for sale, Fair Value	395,290		390,385
Equity Securities-Financial Services [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	25		25
Available for sale, Fair Value	$ 25		$ 25

Investment Securities - Schedul

Investment Securities - Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Detail) $ in Thousands	Mar. 31, 2017USD ($)
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Due in one year or less, Amortized Cost	$ 15,986
Due after one year through five years, Amortized Cost	35,680
Due after five years through ten years, Amortized Cost	92,538
Due after ten years, Amortized Cost	254,146
Total, Amortized Cost	398,350
Due in one year or less, Fair Value	16,013
Due after one year through five years, Fair Value	35,666
Due after five years through ten years, Fair Value	92,271
Due after ten years, Fair Value	251,340
Total, Fair Value	$ 395,290

Investment Securities - Additio

Investment Securities - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Realized gross gains	$ 0		$ 365,000	$ 0	$ 368,000
Realized gross losses	$ 0		0	$ 0	0
Proceeds from the sale of investment securities			$ 17,400,000		$ 29,000,000
Eagle National Bancorp, Inc [Member]
Schedule of Available-for-sale Securities [Line Items]
Realized gross gains		$ 0
Realized gross losses		0
Proceeds from the sale of investment securities		$ 16,200,000

Investment Securities - Sched38

Investment Securities - Schedule of Gross Unrealized Losses and Fair Value (Detail) $ in Thousands	Mar. 31, 2017USD ($)Security	Sep. 30, 2016USD ($)Security
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	190	70
Fair Value, Less than Twelve Months	$ 216,767	$ 48,782
Gross Unrealized Losses, Less than Twelve Months	(4,031)	(411)
Fair Value, Twelve Months or Greater	35,109	32,120
Gross Unrealized Losses, Twelve Months or Greater	(1,138)	(668)
Fair Value, Total	251,876	80,902
Gross Unrealized Losses, Total	$ (5,169)	$ (1,079)
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	61	17
Fair Value, Less than Twelve Months	$ 76,418	$ 6,841
Gross Unrealized Losses, Less than Twelve Months	(1,192)	(21)
Fair Value, Twelve Months or Greater	11,033	12,261
Gross Unrealized Losses, Twelve Months or Greater	(399)	(152)
Fair Value, Total	87,451	19,102
Gross Unrealized Losses, Total	$ (1,591)	$ (173)
Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	50	11
Fair Value, Less than Twelve Months	$ 66,922	$ 7,457
Gross Unrealized Losses, Less than Twelve Months	(909)	(11)
Fair Value, Twelve Months or Greater	6,701	6,375
Gross Unrealized Losses, Twelve Months or Greater	(227)	(74)
Fair Value, Total	73,623	13,832
Gross Unrealized Losses, Total	$ (1,136)	$ (85)
Governmental National Mortgage Association [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	9	5
Fair Value, Less than Twelve Months	$ 7,292	$ 4,704
Gross Unrealized Losses, Less than Twelve Months	(181)	(16)
Fair Value, Twelve Months or Greater	2,373	1,267
Gross Unrealized Losses, Twelve Months or Greater	(37)	(12)
Fair Value, Total	9,665	5,971
Gross Unrealized Losses, Total	$ (218)	$ (28)
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	29	12
Fair Value, Less than Twelve Months	$ 34,982	$ 14,420
Gross Unrealized Losses, Less than Twelve Months	(974)	(65)
Fair Value, Total	34,982	14,420
Gross Unrealized Losses, Total	$ (974)	$ (65)
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	23	12
Fair Value, Less than Twelve Months	$ 18,850	$ 8,778
Gross Unrealized Losses, Less than Twelve Months	(437)	(172)
Fair Value, Twelve Months or Greater	6,198	5,303
Gross Unrealized Losses, Twelve Months or Greater	(301)	(340)
Fair Value, Total	25,048	14,081
Gross Unrealized Losses, Total	$ (738)	$ (512)
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	18	13
Fair Value, Less than Twelve Months	$ 12,303	$ 6,582
Gross Unrealized Losses, Less than Twelve Months	(338)	(126)
Fair Value, Twelve Months or Greater	8,804	6,914
Gross Unrealized Losses, Twelve Months or Greater	(174)	(90)
Fair Value, Total	21,107	13,496
Gross Unrealized Losses, Total	$ (512)	$ (216)

Loans Receivable, Net and All39

Loans Receivable, Net and Allowance for Loan Losses - Summary of Loans Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015
Real estate loans:
Total Loans	$ 1,217,863		$ 1,228,269
Less allowance for loan losses	9,366	$ 9,342	9,056	$ 9,415	$ 9,257	$ 8,919
Net loans	1,208,497		1,219,213
Residential Real Estate Loans [Member]
Real estate loans:
Total Loans	592,169		596,645
Less allowance for loan losses	4,130	4,450	4,426	4,655	4,747	5,140
Construction Real Estate Loans [Member]
Real estate loans:
Total Loans	3,928		1,733
Commercial Real Estate Loans [Member]
Real estate loans:
Total Loans	290,411		288,447
Less allowance for loan losses	1,038	795	852	968	858	671
Commercial Loans [Member]
Real estate loans:
Total Loans	34,125		39,978
Less allowance for loan losses	951	965	882	738	705	693
Obligations of States and Political Subdivisions [Member]
Real estate loans:
Total Loans	61,746		56,923
Less allowance for loan losses	244	234	215	196	187	189
Home Equity Loans and Lines of Credit [Member]
Real estate loans:
Total Loans	45,651		48,163
Less allowance for loan losses	445	441	455	389	389	461
Auto Loans [Member]
Real estate loans:
Total Loans	186,697		193,078
Less allowance for loan losses	1,908	2,062	1,880	1,925	1,754	1,570
Other [Member]
Real estate loans:
Total Loans	3,136		3,302
Less allowance for loan losses	$ 24	$ 25	$ 25	$ 25	$ 27	$ 27

Loans Receivable, Net and All40

Loans Receivable, Net and Allowance for Loan Losses - Additional Information (Detail)	Dec. 04, 2015USD ($)	Mar. 31, 2017USD ($)Contract	Mar. 31, 2016USD ($)Contract	Mar. 31, 2017USD ($)Contract	Mar. 31, 2016USD ($)Contract	Sep. 30, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 3,468,000	$ 23,854,000		$ 23,854,000		$ 27,215,000
Estimated fair value	1,972,000
Contractual cash flows	4,185,000
Preliminary estimate of expected cash flows	2,212,000
Non-accretable discount	1,973,000
Cash flows in excess of estimated fair value	$ 240,000
Criteria in internal rating system				Ten-point
Categories considered as not criticized				six
Days past due over which loans are considered as substandard				90 days
Minimum internal review amount		750,000		$ 750,000
Minimum external review amount		$ 1,000,000		$ 1,000,000
Number of Contracts | Contract		3	4	5	5
Number of troubled debt restructuring loans granted terms concessions | Contract		1	1	1	2
Troubled debt restructurings granted terms concession		$ 135,000	$ 15,000	$ 135,000	$ 96,000
Number of troubled debt restructuring loans granted terms and rate concessions | Contract		1	2	3	2
Troubled debt restructurings granted terms and rate concession		$ 132,000	$ 572,000	$ 376,000	$ 572,000
Number of troubled debt restructuring loans granted interest rate concession | Contract		1	1	1	1
Troubled debt restructurings loans granted interest rate concession		$ 24,000	$ 77,000	$ 24,000	$ 77,000
Number of troubled debt restructurings, loan modified, defaulted within one year of modification | Contract		0	0	1	0
Troubled debt restructurings, loan modified, defaulted within one year of modification				$ 107,000
Foreclosed assets		$ 3,300,000		3,300,000		$ 2,700,000
Consumer Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosed assets		2,100,000		2,100,000
Formal foreclosure proceeding assets		2,200,000		2,200,000
Eagle National Bancorp, Inc [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		3,500,000		3,500,000
Estimated fair value				2,000,000
Contractual cash flows		4,200,000		4,200,000
Preliminary estimate of expected cash flows		2,200,000		2,200,000
Non-accretable discount				2,000,000
Cash flows in excess of estimated fair value		240,000		240,000
Loans Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of Purchased loans		$ 5,100,000		$ 5,100,000

Loans Receivable, Net and All41

Loans Receivable, Net and Allowance for Loan Losses - Schedule of Investment and Unpaid Principal Balances for Impaired Loans (Detail) - USD ($) $ in Thousands	Dec. 04, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Sep. 30, 2016
Financing Receivable, Impaired [Line Items]
Recorded Investment		$ 20,315		$ 20,315			$ 22,565
Unpaid Principal Balance	$ 3,468	23,854		23,854			27,215
Associated Allowance		485		485		$ 485	347
Average Recorded Investment		19,462	$ 26,622	20,677	$ 27,086
Interest	717	107	196	261	423
Contractual cash flows	4,185
Non-accretable discount	(1,973)
Expected cash flows	2,212
Accretable discount	(240)
Estimated fair value	$ 1,972
With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		17,773		17,773			19,994
Unpaid Principal Balance		20,957		20,957			24,488
Average Recorded Investment		16,740	22,165	17,991	23,225
Interest		105	190	255	411
With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		2,542		2,542			2,571
Unpaid Principal Balance		2,897		2,897			2,727
Associated Allowance		485		485			347
Average Recorded Investment		2,722	4,457	2,686	3,861
Interest		2	6	6	12
Residential Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		7,011		7,011			8,721
Unpaid Principal Balance		9,145		9,145			11,167
Associated Allowance		128		128			198
Average Recorded Investment		7,558	9,975	8,074	10,676
Interest		9	26	21	57
Residential Real Estate Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		5,351		5,351			6,721
Unpaid Principal Balance		7,155		7,155			9,016
Average Recorded Investment		5,573	7,296	6,049	8,040
Interest		9	22	21	48
Residential Real Estate Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		1,660		1,660			2,000
Unpaid Principal Balance		1,990		1,990			2,151
Associated Allowance		128		128			198
Average Recorded Investment		1,985	2,679	2,025	2,636
Interest			4		9
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		10,542		10,542			11,237
Unpaid Principal Balance		11,697		11,697			13,231
Associated Allowance		26		26			36
Average Recorded Investment		9,559	13,618	10,235	13,882
Interest		67	131	172	307
Commercial Real Estate Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		10,422		10,422			10,939
Unpaid Principal Balance		11,569		11,569			12,928
Average Recorded Investment		9,218	12,128	9,890	12,908
Interest		67	131	172	307
Commercial Real Estate Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		120		120			298
Unpaid Principal Balance		128		128			303
Associated Allowance		26		26			36
Average Recorded Investment		341	1,490	345	974
Commercial Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		1,742		1,742			1,698
Unpaid Principal Balance		1,826		1,826			1,725
Associated Allowance		125		125
Average Recorded Investment		1,737	1,925	1,724	1,354
Interest		29	37	62	52
Commercial Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		1,557		1,557			1,698
Unpaid Principal Balance		1,627		1,627			1,725
Average Recorded Investment		1,637	1,919	1,665	1,350
Interest		29	37	62	52
Commercial Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		185		185
Unpaid Principal Balance		199		199
Associated Allowance		125		125
Average Recorded Investment		100	6	59	4
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		216		216			361
Unpaid Principal Balance		292		292			432
Associated Allowance		5		5
Average Recorded Investment		207	653	264	738
Interest					2
Home Equity Loans and Lines of Credit [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		211		211			361
Unpaid Principal Balance		287		287			432
Average Recorded Investment		202	594	260	672
Interest					2
Home Equity Loans and Lines of Credit [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		5		5
Unpaid Principal Balance		5		5
Associated Allowance		5		5
Average Recorded Investment		5	59	4	66
Auto Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		780		780			526
Unpaid Principal Balance		865		865			638
Associated Allowance		201		201			113
Average Recorded Investment		393	450	372	436
Interest		2	2	6	5
Auto Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		208		208			253
Unpaid Principal Balance		290		290			365
Average Recorded Investment		102	228	119	255
Interest					2
Auto Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		572		572			273
Unpaid Principal Balance		575		575			273
Associated Allowance		201		201			113
Average Recorded Investment		291	222	253	181
Interest		2	2	6	$ 3
Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		24		24			22
Unpaid Principal Balance		29		29			22
Average Recorded Investment		8	1	8
Other [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		24		24			22
Unpaid Principal Balance		29		29			$ 22
Average Recorded Investment		$ 8		$ 8
Other [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment			$ 1

Loans Receivable, Net and All42

Loans Receivable, Net and Allowance for Loan Losses - Changes in Accretable Yield for Purchased Credit-Impaired Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Receivables [Abstract]
Balance at beginning of period	$ 453	$ 448	$ 478	$ 258
Reclassification, new additions and other	82		118	240
Accretion	(75)	(83)	(136)	(133)
Balance at end of period	$ 460	$ 365	$ 460	$ 365

Loans Receivable, Net and All43

Loans Receivable, Net and Allowance for Loan Losses - Summary of Additional Information Regarding Loans Acquired and Accounted (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 1,217,863	$ 1,228,269
Loans Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	6,309	6,893
Carrying amount	$ 5,098	$ 5,563

Loans Receivable, Net and All44

Loans Receivable, Net and Allowance for Loan Losses - Schedule of Loans Evaluated for Impairment (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,217,863	$ 1,228,269
Individually Evaluated for Impairment	20,315	22,565
Collectively Evaluated for Impairment	1,192,450	1,200,141
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,098	5,563
Residential Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	592,169	596,645
Individually Evaluated for Impairment	7,011	8,721
Collectively Evaluated for Impairment	585,158	587,924
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	290,411	288,447
Individually Evaluated for Impairment	10,542	11,237
Collectively Evaluated for Impairment	275,416	272,595
Commercial Real Estate Loans [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,453	4,615
Commercial Real Estate Loans [Member] | Construction Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,928	1,733
Collectively Evaluated for Impairment	3,928	1,733
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	34,125	39,978
Individually Evaluated for Impairment	1,742	1,698
Collectively Evaluated for Impairment	32,062	37,869
Commercial Loans [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	321	411
Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	61,746	56,923
Collectively Evaluated for Impairment	61,746	56,923
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	45,651	48,163
Individually Evaluated for Impairment	216	361
Collectively Evaluated for Impairment	45,111	47,265
Home Equity Loans and Lines of Credit [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	324	537
Auto Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	186,697	193,078
Individually Evaluated for Impairment	780	526
Collectively Evaluated for Impairment	185,917	192,552
Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,136	3,302
Individually Evaluated for Impairment	24	22
Collectively Evaluated for Impairment	$ 3,112	$ 3,280

Loans Receivable, Net and All45

Loans Receivable, Net and Allowance for Loan Losses - Classes of Loan Portfolio, Internal Risk Rating System (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	$ 1,208,497	$ 1,219,213
Commercial And Municipal Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	386,282	385,348
Commercial And Municipal Portfolio Segment | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	290,411	288,447
Commercial And Municipal Portfolio Segment | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	34,125	39,978
Commercial And Municipal Portfolio Segment | Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	61,746	56,923
Pass [Member] | Commercial And Municipal Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	359,271	353,695
Pass [Member] | Commercial And Municipal Portfolio Segment | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	266,868	260,088
Pass [Member] | Commercial And Municipal Portfolio Segment | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	30,657	36,684
Pass [Member] | Commercial And Municipal Portfolio Segment | Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	61,746	56,923
Special Mention [Member] | Commercial And Municipal Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	5,402	9,066
Special Mention [Member] | Commercial And Municipal Portfolio Segment | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	5,225	8,886
Special Mention [Member] | Commercial And Municipal Portfolio Segment | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	177	180
Substandard [Member] | Commercial And Municipal Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	21,609	22,587
Substandard [Member] | Commercial And Municipal Portfolio Segment | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	18,318	19,473
Substandard [Member] | Commercial And Municipal Portfolio Segment | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	$ 3,291	$ 3,114

Loans Receivable, Net and All46

Loans Receivable, Net and Allowance for Loan Losses - Schedule of Performing or Non-Performing Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1,208,497	$ 1,219,213
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	831,581	842,921
Purchase Credit Impaired [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	324	537
Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	822,534	832,624
Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	8,723	9,760
Residential Real Estate Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	592,169	596,645
Residential Real Estate Loans [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	584,544	587,673
Residential Real Estate Loans [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	7,625	8,972
Commercial Real Estate Loans [Member] | Construction Real Estate Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,928	1,733
Commercial Real Estate Loans [Member] | Performing [Member] | Construction Real Estate Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,928	1,733
Home Equity Loans and Lines of Credit [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	45,651	48,163
Home Equity Loans and Lines of Credit [Member] | Purchase Credit Impaired [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	324	537
Home Equity Loans and Lines of Credit [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	45,053	47,213
Home Equity Loans and Lines of Credit [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	274	413
Auto Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	186,697	193,078
Auto Loans [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	185,907	192,734
Auto Loans [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	790	344
Other [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,136	3,302
Other [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,102	3,271
Other [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 34	$ 31

Loans Receivable, Net and All47

Loans Receivable, Net and Allowance for Loan Losses - Classes of Loan Portfolio Summarized by Aging Categories (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 1,197,401	$ 1,204,129
31-60 Days Past Due	1,938	3,538
61-90 Days Past Due	689	1,287
Non-accrual	12,737	13,752
Total Past Due	15,364	18,577
Purchased Credit Impaired	5,098	5,563
Total Loans	1,217,863	1,228,269
Residential Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	582,864	585,517
31-60 Days Past Due	1,081	1,496
61-90 Days Past Due	599	660
Non-accrual	7,625	8,972
Total Past Due	9,305	11,128
Total Loans	592,169	596,645
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,928	1,733
Total Loans	3,928	1,733
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	282,390	279,019
31-60 Days Past Due	284	1,093
61-90 Days Past Due		191
Non-accrual	3,284	3,529
Total Past Due	3,568	4,813
Purchased Credit Impaired	4,453	4,615
Total Loans	290,411	288,447
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	32,994	38,862
31-60 Days Past Due	80	185
61-90 Days Past Due		57
Non-accrual	730	463
Total Past Due	810	705
Purchased Credit Impaired	321	411
Total Loans	34,125	39,978
Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	61,746	56,923
Total Loans	61,746	56,923
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	45,027	47,026
31-60 Days Past Due	18	40
61-90 Days Past Due	8	147
Non-accrual	274	413
Total Past Due	300	600
Purchased Credit Impaired	324	537
Total Loans	45,651	48,163
Auto Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	185,398	191,785
31-60 Days Past Due	427	717
61-90 Days Past Due	82	232
Non-accrual	790	344
Total Past Due	1,299	1,293
Total Loans	186,697	193,078
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,054	3,264
31-60 Days Past Due	48	7
Non-accrual	34	31
Total Past Due	82	38
Total Loans	$ 3,136	$ 3,302

Loans Receivable, Net and All48

Loans Receivable, Net and Allowance for Loan Losses - Summary of Primary Segments of ALL (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	$ 9,342	$ 9,257	$ 9,056	$ 8,919
Individually evaluated for impairment	485		485		$ 347
Charge-offs	(969)	(580)	(1,675)	(887)
Collectively evaluated for impairment	8,881		8,881		8,709
Recoveries	243	138	485	183
Provision	750	600	1,500	1,200
Balance, End of period	9,366	9,415	9,366	9,415
Residential Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	4,450	4,747	4,426	5,140
Individually evaluated for impairment	128		128		198
Charge-offs	(290)	(308)	(366)	(399)
Collectively evaluated for impairment	4,002		4,002		4,228
Recoveries	5		6	3
Provision	(35)	216	64	(89)
Balance, End of period	4,130	4,655	4,130	4,655
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	795	858	852	671
Individually evaluated for impairment	26		26		36
Charge-offs	(128)	(9)	(218)	(9)
Collectively evaluated for impairment	1,012		1,012		816
Recoveries		52	10	52
Provision	371	67	394	254
Balance, End of period	1,038	968	1,038	968
Commercial Real Estate Loans [Member] | Construction Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	23	14	13	7
Collectively evaluated for impairment	30		30		13
Provision	7	10	17	17
Balance, End of period	30	24	30	24
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	965	705	882	693
Individually evaluated for impairment	125		125
Charge-offs	(1)		(20)	(3)
Collectively evaluated for impairment	826		826		882
Recoveries				1
Provision	(13)	33	89	47
Balance, End of period	951	738	951	738
Obligations of States and Political Subdivisions [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	234	187	215	189
Collectively evaluated for impairment	244		244		215
Provision	10	9	29	7
Balance, End of period	244	196	244	196
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	441	389	455	461
Individually evaluated for impairment	5		5
Charge-offs	(6)	(29)	(6)	(54)
Collectively evaluated for impairment	440		440		455
Recoveries	2	3	3	4
Provision	8	26	(7)	(22)
Balance, End of period	445	389	445	389
Auto Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	2,062	1,754	1,880	1,570
Individually evaluated for impairment	201		201		113
Charge-offs	(544)	(234)	(1,061)	(422)
Collectively evaluated for impairment	1,707		1,707		1,767
Recoveries	232	80	460	117
Provision	158	325	629	660
Balance, End of period	1,908	1,925	1,908	1,925
Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	25	27	25	27
Charge-offs			(4)
Collectively evaluated for impairment	24		24		25
Recoveries	4	3	6	6
Provision	(5)	(5)	(3)	(8)
Balance, End of period	24	25	24	25
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	347	576	308	161
Collectively evaluated for impairment	596		596		$ 308
Provision	249	(81)	288	334
Balance, End of period	$ 596	$ 495	$ 596	$ 495

Loans Receivable, Net and All49

Loans Receivable, Net and Allowance for Loan Losses - Summary of Troubled Debt Restructuring Granted (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017USD ($)Contract	Mar. 31, 2016USD ($)Contract	Mar. 31, 2017USD ($)Contract	Mar. 31, 2016USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	3	4	5	5
Real Estate Loans [Member] | Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	3	3	4
Pre-Modification Outstanding Recorded Investment	$ 135	$ 587	$ 379	$ 668
Post-Modification Outstanding Recorded Investment	$ 135	$ 587	$ 379	$ 668
Real Estate Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 132	$ 77	$ 132	$ 77
Post-Modification Outstanding Recorded Investment	$ 132	$ 77	$ 132	$ 77
Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1		1
Pre-Modification Outstanding Recorded Investment	$ 24		$ 24
Post-Modification Outstanding Recorded Investment	$ 24		$ 24
Troubled Debt Restructurings [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	3	4	5	5
Pre-Modification Outstanding Recorded Investment	$ 291	$ 664	$ 535	$ 745
Post-Modification Outstanding Recorded Investment	$ 291	$ 664	$ 535	$ 745

Deposits - Schedule of Deposits

Deposits - Schedule of Deposits by Major Classifications (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016
Banking And Thrift [Abstract]
Non-interest bearing demand accounts	$ 150,762	$ 142,924
Interest bearing demand accounts	139,528	167,259
Money market accounts	255,502	249,947
Savings and club accounts	145,478	142,021
Certificates of deposit	547,105	512,669
Total	$ 1,238,375	$ 1,214,820

Net Periodic Benefit Cost-Def51

Net Periodic Benefit Cost-Defined Benefit Plan - Summary of the Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Compensation Related Costs [Abstract]
Service Cost	$ 69	$ 249	$ 378	$ 498
Interest Cost	208	245	443	490
Expected return on plan assets	(348)	(311)	(689)	(622)
Amortization of unrecognized loss	23	119	159	239
Net periodic benefit cost	$ (48)	$ 302	$ 291	$ 605

Net Periodic Benefit Cost-Def52

Net Periodic Benefit Cost-Defined Benefit Plan - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Compensation And Retirement Disclosure [Abstract]
Projected benefit obligation	$ (7,100)
Tax effected	$ 4,727	$ 79	$ 4,817	$ 158

Equity Incentive Plan - Additio

Equity Incentive Plan - Additional Information (Detail) - USD ($)	Mar. 29, 2017	Dec. 13, 2016	Mar. 04, 2016	May 20, 2015	Jul. 22, 2014	Apr. 01, 2013	May 23, 2008	Mar. 31, 2017	Mar. 31, 2016
Compensation Related Costs Disclosure [Line Items]
Stock option granted								0
Option vesting period								5 years
Option expiration period								10 years
Share-based compensation expense								$ 145,000	$ 79,000
Equity Incentive Plan [Member]
Compensation Related Costs Disclosure [Line Items]
Common stock issuance, Grant								2,377,326
2016 Plan [Member]
Compensation Related Costs Disclosure [Line Items]
Common stock issuance, Grant								250,000
Further number of shares, grants								0
Stock Option [Member]
Compensation Related Costs Disclosure [Line Items]
Number of available shares								1,698,090
Restricted Stock [Member]
Compensation Related Costs Disclosure [Line Items]
Number of available shares								679,236
Restricted stock granted	3,296	20,675	23,491	21,843	19,880	30,000	590,320
Share-based compensation expense								$ 145,000	$ 79,000
Restricted Stock [Member] | 2013 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								18 months
Restricted Stock [Member] | 2014 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								39 months
Expected future expense								$ 32,000
Remaining vesting periods								6 months
Restricted Stock [Member] | 2015 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								40 months
Expected future expense								$ 123,000
Remaining vesting periods								1 year 6 months
Restricted Stock [Member] | March 4, 2016 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								43 months
Restricted Stock [Member] | 12/13/16 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								46 months
Restricted Stock [Member] | March 29, 2017 [Member] | Tranche One [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								42 months
Restricted shares vested, Number of shares								1,296
Expected future expense								$ 19,000
Remaining vesting periods								3 years 6 months
Outstanding nonvested restricted stock								1,296
Restricted Stock [Member] | March 29, 2017 [Member] | Tranche Two [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period								18 months
Restricted shares vested, Number of shares								2,000
Expected future expense								$ 29,000
Remaining vesting periods								1 year 6 months
Outstanding nonvested restricted stock								2,000
Restricted Stock [Member] | 2016 [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense								$ 213,000
Remaining vesting periods								2 years 6 months
Restricted Stock [Member] | December Two Thousand Sixteen Plan
Compensation Related Costs Disclosure [Line Items]
Expected future expense								$ 313,000
Remaining vesting periods								3 years 6 months
Non Qualified Stock Option [Member]
Compensation Related Costs Disclosure [Line Items]
Stock option granted							1,140,469
Incentive Stock Option [Member]
Compensation Related Costs Disclosure [Line Items]
Stock option granted							317,910

Equity Incentive Plan - Schedul

Equity Incentive Plan - Schedule of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Stock Options, Outstanding, September 30, 2016	905,987
Number of Stock Options, Granted	0
Number of Stock Options, Exercised	488,491
Number of Stock Options, Forfeited	0
Number of Stock Options, Outstanding, March 31, 2017	417,496	905,987
Number of Stock Options, Exercisable at year-end	417,496
Weighted-average Exercise Price, Outstanding, September 30, 2016	$ 12.35
Weighted-average Exercise Price, Granted	0
Weighted-average Exercise Price, Exercised	12.35
Weighted-average Exercise Price, Forfeited	0
Weighted-average Exercise Price, Outstanding, March 31, 2017	12.35	$ 12.35
Weighted-average Exercise Price, Exercisable at year-end	$ 12.35
Weighted-average Remaining Contractual Term (in years), Outstanding	1 year 5 months 1 day	1 year 8 months 1 day
Weighted-average Remaining Contractual Term (in years), Granted	0 years
Weighted-average Remaining Contractual Term (in years), Exercised	1 year 5 months 1 day
Weighted-average Remaining Contractual Term (in years), Forfeited	0 years
Weighted-average Remaining Contractual Term (in years), Exercisable	1 year 5 months 1 day
Aggregate Intrinsic Value, Outstanding, Beginning Balance	$ 1,341
Aggregate Intrinsic Value, Granted	0
Aggregate Intrinsic Value, Exercised	0
Aggregate Intrinsic Value, Forfeited	0
Aggregate Intrinsic Value, Outstanding, Ending Balance	932	$ 1,341
Aggregate Intrinsic Value, Exercisable at year-end	$ 932

Equity Incentive Plan - Sched55

Equity Incentive Plan - Schedule of Restricted Stock Option Activity (Detail) - Restricted Stock [Member]	6 Months Ended
	Mar. 31, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Restricted Stock, Nonvested at September 30, 2016 | shares	31,896
Number of Restricted Stock, Granted | shares	23,971
Number of Restricted Stock, Vested | shares	0
Number of Restricted Stock, Forfeited | shares	0
Number of Restricted Stock, Nonvested at March 31, 2017 | shares	55,867
Weighted-average Grant Date Fair Value, Nonvested at September 30, 2016 | $ / shares	$ 13.11
Weighted-average Grant Date Fair Value, Granted | $ / shares	16.28
Weighted-average Grant Date Fair Value, Vested | $ / shares	0
Weighted-average Grant Date Fair Value, Forfeited | $ / shares	0
Weighted-average Grant Date Fair Value, Nonvested at March 31, 2017 | $ / shares	$ 14.50

Fair Value Measurement - Schedu

Fair Value Measurement - Schedule of Securities, Derivatives, Other Real Estate Owned and Impaired Loans Measured at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	$ 395,315	$ 395,315	$ 390,410
Derivatives		1,397	453
Foreclosed real estate	3,315		2,659
Impaired loans		19,830	22,218
Mortgage servicing rights		321	398
Fair Value, Measurements, Nonrecurring [Member]
Securities available-for-sale measured on a recurring basis
Foreclosed real estate		3,315	2,659
Mortgage-Backed Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities		228,122	219,162
Obligations of States and Political Subdivisions [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities		69,335	73,690
U.S. Government Agency Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities		23,463	25,941
Corporate Obligations [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities		44,780	38,418
Other Debt Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities		29,590	33,174
Equity Securities-Financial Services [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities		$ 25	25
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	25		25
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities-Financial Services [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	25		25
Significant Other Observable Inputs (Level 2) [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	386,555		382,900
Derivatives	1,397		453
Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	228,122		219,162
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	69,335		73,690
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Agency Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	23,463		25,941
Significant Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	36,045		31,433
Significant Other Observable Inputs (Level 2) [Member] | Other Debt Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	29,590		32,674
Significant Unobservable Inputs (Level 3) [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	8,735		7,485
Impaired loans	19,830		22,218
Mortgage servicing rights	321		398
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member]
Securities available-for-sale measured on a recurring basis
Foreclosed real estate	3,315		2,659
Significant Unobservable Inputs (Level 3) [Member] | Corporate Obligations [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities	$ 8,735		6,985
Significant Unobservable Inputs (Level 3) [Member] | Other Debt Securities [Member]
Securities available-for-sale measured on a recurring basis
Total debt and equity securities			$ 500

Fair Value Measurement - Sche57

Fair Value Measurement - Schedule of Changes in Fair Value of Level III Investments (Detail) - Significant Unobservable Inputs (Level 3) [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 8,238	$ 7,136	$ 7,485	$ 4,211
Purchases, sales, issuances, settlements, net	756		756	3,000
Total unrealized gain (loss):
Included in other comprehensive income	(259)	(64)	494	(139)
Ending balance	$ 8,735	$ 7,072	$ 8,735	$ 7,072

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016USD ($)Loan	Sep. 30, 2016USD ($)Loan	Mar. 31, 2017USD ($)
Fair Value Disclosures [Abstract]
Number of impaired loans | Loan	177	205
Impaired loans, carrying value	$ 20,300	$ 22,600
Impaired loans, valuation allowance	485	347	$ 485
Impaired loans, net fair value	$ 19,800	$ 22,200

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Additional Quantitative Information about Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Prepayment speeds	Prepayment speeds
Fair value input appraisal adjustments	15.00%	17.20%
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	9.00%	2.00%
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	35.00%	33.00%
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Estimate	$ 19,830	$ 22,218
Unobservable Input	Appraisal adjustments	Appraisal adjustments
Fair value input appraisal adjustments	23.40%	23.00%
Impaired Loans [Member] | Appraisal of Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Impaired Loans [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	0.00%	0.00%
Impaired Loans [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	50.00%	60.00%
Foreclosed Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Estimate	$ 3,315	$ 2,659
Unobservable Input	Appraisal adjustments	Appraisal adjustments
Fair value input appraisal adjustments	21.00%	22.10%
Foreclosed Real Estate Owned [Member] | Appraisal of Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Foreclosed Real Estate Owned [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	20.00%	20.00%
Foreclosed Real Estate Owned [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	50.00%	46.00%
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Estimate	$ 321	$ 398
Unobservable Input	Discount rate	Discount rate
Fair value input appraisal adjustments	12.50%	12.00%
Mortgage Servicing Rights [Member] | Appraisal of Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Techniques	Discounted cash flow	Discounted cash flow
Mortgage Servicing Rights [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	12.00%	12.00%
Mortgage Servicing Rights [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	16.00%	16.00%

Fair Value Measurement - Sche60

Fair Value Measurement - Schedule of Estimate of Fair Value Using Methodologies (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Financial assets:
Investment and mortgage backed securities available for sale	$ 395,315	$ 395,315	$ 390,410
Loans receivable, net		19,800	22,200
Mortgage servicing rights		321	398
Derivatives		$ 1,397	453
Bank-owned life insurance	37,112		36,593
Financial liabilities:
Other borrowings	199,168		230,601
Advances by borrowers for taxes and insurance	9,115		4,956
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	25		25
Significant Other Observable Inputs (Level 2) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	386,555		382,900
Derivatives	1,397		453
Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	8,735		7,485
Mortgage servicing rights	321		398
Carrying Value [Member]
Financial assets:
Cash and cash equivalents	36,443		43,658
Certificates of deposit	1,000		1,250
Investment and mortgage backed securities available for sale	395,315		390,410
Loans receivable, net	1,208,497		1,219,213
Accrued interest receivable	5,929		5,769
Regulatory stock	13,961		15,463
Mortgage servicing rights	321		398
Derivatives	1,397		453
Bank-owned life insurance	37,112		36,593
Financial liabilities:
Deposits	1,238,375		1,214,820
Short-term borrowings	120,951		129,460
Other borrowings	199,168		230,601
Advances by borrowers for taxes and insurance	9,115		4,956
Accrued interest payable	863		1,046
Estimated Fair Value [Member]
Financial assets:
Cash and cash equivalents	36,443		43,658
Certificates of deposit	1,010		1,269
Investment and mortgage backed securities available for sale	395,315		390,410
Loans receivable, net	1,203,706		1,237,759
Accrued interest receivable	5,929		5,769
Regulatory stock	13,961		15,463
Mortgage servicing rights	321		398
Derivatives	1,397		453
Bank-owned life insurance	37,112		36,593
Financial liabilities:
Deposits	1,239,472		1,218,894
Short-term borrowings	120,951		129,460
Other borrowings	199,219		231,911
Advances by borrowers for taxes and insurance	9,115		4,956
Accrued interest payable	863		1,046
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Cash and cash equivalents	36,443		43,658
Investment and mortgage backed securities available for sale	25		25
Accrued interest receivable	5,929		5,769
Regulatory stock	13,961		15,463
Bank-owned life insurance	37,112		36,593
Financial liabilities:
Deposits	691,270		702,151
Short-term borrowings	120,951		129,460
Advances by borrowers for taxes and insurance	9,115		4,956
Accrued interest payable	863		1,046
Estimated Fair Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	386,555		382,900
Derivatives	1,397		453
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Certificates of deposit	1,010		1,269
Investment and mortgage backed securities available for sale	8,735		7,485
Loans receivable, net	1,203,706		1,237,759
Mortgage servicing rights	321		398
Financial liabilities:
Deposits	548,202		516,743
Other borrowings	$ 199,219		$ 231,911

Accumulated Other Comprehensi61

Accumulated Other Comprehensive Loss - Summary of Activity in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Beginning Balance			$ 176,344
Total other comprehensive income (loss)	$ 5,531	$ 3,125	(532)	$ 958
Ending Balance	178,769		178,769
Defined Benefit Pension Plan [Member]
Schedule of Available-for-sale Securities [Line Items]
Beginning Balance	(5,993)	(5,246)	(6,083)	(5,325)
Other comprehensive income (loss) before reclassifications	4,714		4,714
Amounts reclassified from accumulated other comprehensive loss, net of tax	13	79	103	158
Total other comprehensive income (loss)	4,727	79	4,817	158
Ending Balance	(1,266)	(5,167)	(1,266)	(5,167)
Unrealized Gains (Losses) on Securities Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Beginning Balance	(2,801)	684	3,952	2,930
Other comprehensive income (loss) before reclassifications	781	3,287	(5,972)	1,043
Amounts reclassified from accumulated other comprehensive loss, net of tax		(241)		(243)
Total other comprehensive income (loss)	781	3,046	(5,972)	800
Ending Balance	(2,020)	3,730	(2,020)	3,730
Derivatives [Member]
Schedule of Available-for-sale Securities [Line Items]
Beginning Balance	899		299
Other comprehensive income (loss) before reclassifications	25		619
Amounts reclassified from accumulated other comprehensive loss, net of tax	(2)		4
Total other comprehensive income (loss)	23		623
Ending Balance	922		922
Accumulated Other Comprehensive Loss [Member]
Schedule of Available-for-sale Securities [Line Items]
Beginning Balance	(7,895)	(4,562)	(1,832)	(2,395)
Other comprehensive income (loss) before reclassifications	5,520	3,287	(639)	1,043
Amounts reclassified from accumulated other comprehensive loss, net of tax	11	(162)	107	(85)
Total other comprehensive income (loss)	5,531	3,125	(532)	958
Ending Balance	$ (2,364)	$ (1,437)	$ (2,364)	$ (1,437)

Accumulated Other Comprehensi62

Accumulated Other Comprehensive Loss - Summary of Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Gain on sale of investments		$ 365		$ 368
Interest expense	$ (3,075)	(2,875)	$ (6,093)	(5,598)
Income taxes	(203)	(726)	(603)	(1,292)
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Available-for-sale Securities [Line Items]
Net of tax	(11)	162	(107)	85
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] | Unrealized Gains (Losses) on Securities Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on sale of investments		365		368
Income taxes		(124)		(125)
Net of tax		241		243
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] | Defined Benefit Pension Plan [Member]
Schedule of Available-for-sale Securities [Line Items]
Income taxes	10	40	56	81
Net of tax	(13)	(79)	(103)	(158)
Compensation and employee benefits	(23)	(119)	(159)	$ (239)
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] | Derivatives [Member]
Schedule of Available-for-sale Securities [Line Items]
Interest expense	5		(6)
Income taxes	(3)		2
Net of tax	$ 2	$ (79)	$ (4)

Derivatives And Hedging Activ63

Derivatives And Hedging Activities - Schedule of Fair Value of Derivative Financial Instruments as well as their Classification on Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Derivatives Fair Value [Line Items]
Fair Values of Derivative Instruments		$ 1,397	$ 453
Designated as Hedging Instrument [Member] | Interest Rate Products [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values of Derivative Instruments	$ 1,397		$ 453

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2017USD ($)Contract	Mar. 31, 2016USD ($)	Mar. 31, 2017USD ($)Contract	Mar. 31, 2016USD ($)	Sep. 30, 2017USD ($)
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Interest income	$ 14,379,000	$ 15,159,000	$ 29,029,000	$ 28,974,000
Interest expense	3,075,000	$ 2,875,000	6,093,000	5,598,000
Increase (decrease) in accrued interest payable			(183,000)	$ 146,000
Net liability position of derivatives	0		0
Minimum [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Debt Instrument, collateral amount	0		0
Designated as Hedging Instrument [Member] | Cash Flow Hedges of Interest Rate Risk [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Interest income	$ 5,000
Interest expense			$ 6,000
Designated as Hedging Instrument [Member] | Cash Flow Hedges of Interest Rate Risk [Member] | Scenario, Forecast [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Increase (decrease) in accrued interest payable					$ 0
Designated as Hedging Instrument [Member] | Cash Flow Hedges of Interest Rate Risk [Member] | Interest Rate Swaps [Member] | Variable Rate [Member] | FHLB Advances [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative, number of instruments | Contract	3		3
Derivative, notional principal amount	$ 50,000,000		$ 50,000,000

Derivatives And Hedging Activ65

Derivatives And Hedging Activities - Schedule of Pre-Tax Net Gains (Losses) of Cash flow Hedges (Detail) - Designated as Hedging Instrument [Member] - Cash Flow Hedges of Interest Rate Risk [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Gain Recognized in OCI on Derivative (Effective Portion)	$ 40	$ 1,092
Gain Reclassified from Accumulated OCI into Income (Effective Portion)	5
(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		(6)
Interest Rate Products [Member]
Derivative Instruments Gain Loss [Line Items]
Gain Recognized in OCI on Derivative (Effective Portion)	40	1,092
Interest Rate Products [Member] | Interest Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Gain Reclassified from Accumulated OCI into Income (Effective Portion)	$ 5
(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		$ (6)